Follow US:

Practice English Speaking&Listening with: Orion Nebula (M42) with a DSLR, Start to Finish - Deep Sky Astrophotography

Normal
(0)
Difficulty: 0

hello welcome to my channel my name is Nico Carver I am a deep sky

astrophotographer and I share these videos with you all to help beginners

who are interested in deep sky astrophotography and with some tips that

I've learned along the way and I also just like sort of sharing what I'm up to

and I'm a gearhead so I talk a lot about the gear that I use and what it does and

we'll start with that today but the this video actually came from a comment on

one of my other videos so I do look at the comments and the comment was from

Patrick Hand who commented can you create a video showing your workflow for

a basic capture of m42 I am new to DSO imaging okay so for

those of you who don't know m42 is Messier 42. Messier was an

astronomer that came up with a list of things that were not comets but that

list is still being used today it's mostly galaxies clusters and nebulae

like the one we're seeing right here this is the Orion Nebula also known as

m42 we're actually seeing more than just m42 here this little part right there is

m-43 and then in the picture that I'm going to capture we'll also get the

Running Man Nebula anyways so the idea basic idea with this video is start to

finish every step how do you make a DSO image so it's going to be probably a

pretty long video I'm gonna start here in the house explaining what equipment

that I'm going to use and why you know I'm using this particular equipment I'm

using pretty beginner equipment and today or tonight and then we'll go on to

setting up the equipment making sure we know how it works then actually setting

it up you know in the location in a dark sight

starting the capture process making sure that we're at the right exposure level

everything looks good capturing what we call our light frames

that's of the actual object so we're gonna try to do maybe I don't know a

hundred 30-second exposures of m42 and see what we get out of that and then

I'll show making the calibration frames those are to help with certain kinds of

noise things like dark current and fixed pattern noise on the sensor we'll get

more into that but they're basically the darks the bias and the flat frames and

we're going to capture each of those and I'll show you how then once we have all

of that data we'll take a look at it what do these things look like in their

raw state and we'll move on to processing now because we could go with

a bunch of different directions and processing in this main video I'm going

to do deep sky stacker and Photoshop deep sky stacker is free and Photoshop

is just really popular so I think a lot of people might be interested in that

combination of programs then I'm gonna have some other videos below this one

where it sort of branches out so you could watch the first half of this video

everything about capture and then switch to another processing video if you don't

use deep sky stacker in Photoshop I'll have one video that goes into doing it

all in pix insight and then another video that shows deep sky stacker + gimp

which is a free Photoshop alternative so if you're a beginner and you don't want

to spend any money on software you can watch that deep sky stacker + gimp video

to show what you could do with just free software because this video is for

people who are new to DSO imaging I want to start with a affordable gear here and

also not over complicate this video because it could go on for hours if I

throw in everything auto guiding and computer control and plate

solving and everything like that so I'm just going to show basically using the

mount with the hand control using a basic telescope and DSLR and that's it

no auto guiding nothing like that short exposures on a bright target let's

break down the gear that we'll use tonight we'll start with this this is

the mount I'm gonna use this is actually just a mount head it goes on a tripod

but this is the part that actually does the work it has the stepper motors

inside here and this is I have a video unboxing this you can watch that if you

want to I've made a few little changes to it I have an adapter so I can use my

qhy pole master for polar alignment it changed out some of the knobs and added

some little waterproof velcro things here to attach different things to it

but other than that it's pretty much stock I'm gonna be using it just with

the hand controller tonight I'm not gonna do computer control and I'm also

just going to be running it off if I can get this open

double-a batteries so eight double a's which is really nice because there's not

going to be any wires hanging off my setup tonight it's been a long time

since I've had an ester photography setup with no wires hanging off but this

is gonna be all running off internal batteries including the mount so that's

gonna be really fun this accepts vixen dovetail and I want to point out that it

might look like I'm endorsing this mount I don't accept any endorsements from any

company I just I've bought this personally the reason I bought it was

for travel because the case for this is small enough that I can bring it

carry-on on an airplane that's the reason I bought this mount it's not

necessarily the mount I would recommend for a beginner amount if you're new to

deep sky astir photography the reason is is it's not going to give you much room

to grow you can't put much weight on it really

only like 10 pounds in under or maybe nine pounds in under and it's not super

accurate it's not like a more you know beefy equatorial mount like in our Ryan

Atlas which is my main one that I use and so it's not going to give you those

results that you're gonna want as a beginner and you're just going to be

fighting it too much so it's not really what I'd recommend if you're new to this

I would save a little bit more buy used do something to get a little bit bigger

mount but I'll try to do a review of this soon because I think it would

really benefit people who want a travel mount that is a full equatorial mount

can do go to can do guiding theoretically still working on that and

so anyways enough said about this the scope that I'm going to be using the

telescope is this one right here this is the as you can see on the side there

Astrotech AT60 ED it's a doublet design the nice thing about a doublet is

that they can stay pretty low weight once you add and now you know the more

elements of glass that you add into a telescope design the heavier it gets the

other nice thing about this scope is like watch this

that's how small it gets so it's very portable I can actually rack the focuser

in here you can see it gets quite small

speaking of the focuser this is the best part of this mount all right I mean

telescope that this is the best part of this telescope that it is 370 dollar

telescope but it actually comes with a really nice two inch rack and pinion

focuser that has all that really works it holds enough weight it has a scale

there on the side it's nice and smooth it has the dual speed I haven't noticed

any backlash so this focuser is rock-solid which is

rare to find on cheap telescopes like this cheap is

relative of course speaking of cheap telescopes you might be wondering well

why would I get something like this with so little aperture win for 4 or $500 I

could instead buy like a fast Newtonian like a six inch or an 8 inch Newtonian

it's a good question the learning curve on a Newtonian is going to be much

steeper and you're probably gonna have to make more upgrades I haven't found

any of those like $400 Newtonian to actually have a good stock focuser so

you'd probably have to replace it so that might double the cost and just you

would also need a much better amount I've struggled with an 8 inch Newtonian

on my Orien Atlas you really want to move up into like holas Mandie or

astrophysics mount probably to really get good results so you're gonna need a

much better amount if you have all the money in the world that might work for

you but if you're looking for something cheap beginner wise this scope I would

recommend or like a 70 millimeter or 80 millimeter or factor would be fine too

but this one is nice and lightweight and like I said three hundred and seventy

dollars there's a couple things I added to it that brought up the total cost to

500 this first one is called the camera angle adjuster and you basically loosen

a screw here and then this whole part right here can now rotate and that's

really nice for framing objects because a lot of

times just the stock rotation you know with the camera level like this is not

gonna really work you don't really want to have to like undo a bunch of threads

and everything to change the rotation of the camera so having a little screw

right there that I can just loosen up and then tighten back down when I got

the angle that I want is really nice this I think was 30 or 40 dollars and

then behind that this is the Astrotech 8086 de d field flattener it

just a field flattener so a lot of times you'll find flatteners also our reducers

meaning they change the focal length and the speed this one doesn't do that it

just flattens the field so this telescope stays at 360 millimeters focal

length but what a field flatter does is normally with a refractor you'll notice

that if you're using a big chip like in a DSLR the center of the field is nice

and flat meaning you have nice round good stars but as you get closer to the

corners and the edges of your frame all the stars start warping and they warp

out towards the corners so you'll see that they have this pattern where

they're going out like this and these bottom corners and out like this and the

top corners and to avoid that the only one thing we can do is get a field

flattener for our telescope or by a design like a quad where the flat inner

element is built into the telescope this is $100 for imaging I think this is

probably essential the camera angle adjuster is not quite as essential but I

would definitely get a field flattener with this telescope and this is just a

forty eight millimeter t2 Canon adapter and then oh and then a vixen plate this

did not come with the telescope you could mount it other ways but I like the

vixen plate especially for most equatorial mounts this is what you would

want these are really cheap though you can get these basically anywhere even

used okay so that's the telescope it's the again the Astrotech 80 60 IDI and

this hanging off the back of it here is the camera that I'll use tonight this is

a Canon t6i it's not modified some people modify their DSLRs they remove

certain low-pass filters and things that are riding in front of the sensor to get

better each a sensitivity this one has not been modified in any way so it's

stock I also have not put on magic lantern firmware which is

something I would usually do because Canon DSLRs do not have usually a

built-in intervalometer meaning a way to take many exposures without touching the

camera so tonight I'll be using a newer or newer just a cheap intervalometer you

can get on Amazon I'll put the link to all this stuff on my website you just

plug this in and then you program how many pictures you want to take and for

how long the delay between the pictures is basically just if I set 30 second

pictures on the camera and then I say take a picture every 35 seconds on here

then there would be a five-second delay between each 30-second exposure the

reason you might want to program a little delay in is because otherwise you

can get a little bit of a vibration effect from the from the mirror closing

and showing all right so intervalometer good easy thing to get about $20 if

you're not comfortable with putting something like magic lantern on your

Canon camera speaking of the camera I'm a Canon person I always have been but

for astrophotography Canon or Nikon DSLRs work really well especially when

you're starting out why not Sony or one of the other brands only

Canon and Nikon DSLRs since about 2011 or 12 have been consistent about not

altering the raw file we'll get more into what or why you want RAW files when

we get into processing but basically you for astrophotography your camera has to

be set to raw and you want just an unadulterated raw file Sony and some of

the other brands have this problem called star eater where the raw is

optimized for daytime use so they lower the some there's some kind of noise

adjustment or something but when you do that for astrophotography it kills a lot

of the dim stars and just no good so canon or nikon DSLR are

definitely the most popular for a reason they also have the most support if you

later on decide you want to hook this up to a laptop there's something called

backyard yose or backyard Nikon that can control the camera for you and then you

wouldn't need this anymore okay so I said just mount scope camera

there's actually one more piece that you would want with a setup like this one

which is some kind of finder if you have a computer controlling everything you

can just plate solve which means it takes a picture of the sky and then it

knows where it's pointed and it can adjust but when you don't have a

computer connected you can't rely just on go to using them out because a lot of

times it's not super accurate until you train them out so what you need is a

some kind of finding device basically just a wider field of view that's going

to point at the sky and sort of tell you where you are pointed so you can make

adjustments I have a bunch of different ones here just to show this first one

that I'm gonna show is a scope stuff green laser and this has a little mount

on it so that I can just put it right there in the shoe mount on the DSLR and

then just press that and I get a laser okay so this would tell me where I'm

pointing it just by shiny and green laser out into the sky and I see that

laser beam going out into the sky and I know where I'm pointed then I like this

a lot it's very easy to use and very

accurate but the problem with using this is right now I'm in a populated area

near the Philadelphia Airport so this is frowned upon because you don't want to

accidentally shine the laser at an airplane and blind the pilot or

something like that so don't use this if you're anywhere near an airport but if

you were out somewhere really dark with no airplanes this might be a good option

another option I use this a lot when I'm doing visual

astronomy this is what's called an RA CI finderscope the RACI stands for right

angle meaning you can look down into it rather than having to be back like that

and the CI means corrected image so it instead of reversing the image in there

its corrected so I really like this very easy to use you can just put this on

either of these little brackets right here and tighten it up and then you have

a nice finder scope I don't usually use this one for astrophotography just

because I don't know why exactly but it's just it's a smaller field of view

and I just find it takes a little bit longer to find things with this for

visual astronomy I don't really care I'm actually with visual astronomy usually

looking at pretty bright objects like the planets and things like that so this

works perfectly fine but for dimmer stuff I like seeing a broader field and

this one sort of limits your field it's probably not much wider field of view

than just looking through the camera so I use this more for visual like when I'm

using a Dobsonian will it show next year tell rad this is probably my favorite of

all the finderscope designs what this does is it has a leveling base so you

can really are leveling thing right there actually so you can really make

sure that it's aligned with your telescope and this also I can just slide

in right here

that and you can see it's sort of elevated and what you do is you just

look with both eyes and you just look right through like that and turn it on

right here and it puts a little red target on to the sky and that's all it

is it just puts a little red target on to the sky right in there and I find

this really easy to use and really accurate because I can just see that red

target and get the object perfectly or the star perfectly centered only

downside with this is that sometimes this piece right here fogs are Frost's

up and then it becomes unusable all right last one you know a lot of finder

options this is the one that I'm planning to use when I'm bringing this

rig traveling because it's the smallest and lightest of all these options this

is a red dot finder this is just a no-name brand red dot finder I got on

Amazon it's also adjustable so you can make sure that you're pointed at the

same thing with this and the telescope before you start finding stuff with it

and then it turns on right here maybe well maybe that was an adjustment whoops

turns on here there we go and so what it does is it puts a little red dot in the

middle of this and then you just look through that again you can just use both

eyes open at the sky and just like this one it just puts a little red target

where you're pointed the only difference between these two really is that this is

just one little harsh red dot and that is a more adjustable big target thing

and so I like that one a little bit better in terms of just looking at it

this one the field of view is a little bit smaller you know this little target

thing you're smaller than that and sometimes I have to sort of squint to

see where exactly I'm pointed with this one but for travel you probably could

can't beat this it's also incredibly lightweight so this adds basically

nothing to the weight of this whole thing right that's enough on finders but

probably essential with something like this where you don't have computer

control to use some kind of finder

okay now I'm gonna go through some tips and things to do with this equipment

before you take it out first thing is if all this equipment is new to you

I don't remem

light or something it's still really hard to really get to know your

equipment for the first time in a dark setting so I would recommend working

with it you know inside or on a sunny day and just really playing around with

it and making sure you understand how everything works another thing you can

do on a sunny day is find the about the right Infinity focus for your telescope

with your DSLR you can just point it at a like a far-off thing like a radio

tower or a cell phone tower and then just wrack the focus in and out until

you have sharp focus and then you can either just leave it like that if that's

an option or you can just note how far out it is this one's really nice because

it has a scale so I can just see okay 22 millimeters out is about the right focus

that's a really nice thing to do before you bring it out under the stars because

one thing that often confuses beginners is if you're too far out of focus like

if I was like that and I looked into my DSLR I probably just wouldn't see

anything even though I'm pointed at the night sky I have my lens cap off it just

looks completely black and a lot of times then a beginner would just assumes

something's really wrong what's going on here this isn't working and you know but

all they would have to do really is just rack the focus in and out and eventually

you'll see the stars come in they'll be really blurry at first and then they'll

get more pinpoint the reason though that when you're really far out of focus it

that you don't see anything is because that light from that stars just scatters

way too much so you just don't see anything in here when you get it closer

and closer that light cone comes together and then

eventually you get those pinpoint stars of just what you want okay and then so

if you have it at about the correct focus when you start then you can just

move to this fine reduction knob and just fine-tune it either by eye you can

just try to get the star as small as possible or you can use a badenov mask

which i've covered in another video but it's basically just a pattern that you

put in front of the scope here and then you make a reproducible pattern on your

live view and you can adjust it until this spike is centered between two other

spikes get one if you've never tried that they're really fun to use other

thing you would want to do before going out other than getting to know your

equipment is make sure you have all fresh batteries fresh SD cards and

backups so I always bring backups of everything I can you know definitely

batteries and memory cards but anything else like even finder scopes I'll bring

backups because things will go wrong you know there's tons of problems at night

due and Frost and all these things and batteries will drain very quickly

because it's cold out so bring backups of everything what else

we want to make sure that we've set a number of camera settings on a DSLR

before we go out because a lot of times if you don't do it before you go out at

night you get excited and you've missed some crucial camera setting like you

have it set on JPEG or something like that and then the night is sort of

ruined so I always make sure that some camera settings you know you can't pick

them all right away but some of the basic ones are set inside before I leave

the house so I'm going to show you a few of those now

okay we're now gonna look at camera settings this is again a Canon t6 I

however I think these camera settings will be will make sense no matter what

model of camera you have but some of them you know in terms of the location

and things and menus might be a little Canon specific but hopefully you'll be

able to find all this stuff in Nikon or whatever camera you have so I've just

turned on the camera it gives me this screen right here which shows me a few

good pieces of information down here this number in the that corner is the

number of exposures that I could do but keep in mind this might be set on JPEG

so this number might be lying right now right there's my battery indicator so I

would always want to make sure I have a charged battery before going out because

I have a telescope attached it automatically switches to manual focus

which is good and it also doesn't give me an option to change the F number

there the aperture setting because it knows that it can't if some on Canon

lenses and lenses meant for this system you could change that number with the

aperture blades you know stopping down the lens but with

the telescope it's fixed is enough six scope in it is always f6 unless you get

a reducer okay anyways that's all that the first thing I noticed here is in the

upper left we're in aperture priority mode for astrophotography we either want

to be in manual exposure mode or if your camera has it bulb mode perhaps if you

want longer than thirty second exposures next thing I'm going to do is we're at

one sixtieth of a second in terms of the shutter speed on a manual mode I'm gonna

change that to six or maybe ten seconds something like that because even if

we're planning to take 30 second exposures and

and when I'm just doing my testing you know testing focus and things like that

under a dark sky I usually want something around five to ten second

exposure some to ten seconds next thing I'm going to do here is I can see we're

on auto white balance I don't want auto white balance I'm

gonna hit Q here move up to that one and change it to daylight white balance if

you are not using any filters and a stock DSLR you want daylight white

balance if you are using something like a light pollution filter you would

instead want to set a custom white balance where with the filter on you go

out and take a picture of something white like a white card with that filter

in there to make a custom white balance but since I'm not using any filters I'm

gonna use daylight white balance if you just leave it on auto white balance

that's not going to be good because it'll change the color temperature of

the scene automatically but it doesn't know what it's doing because it's night

so daylight's better what else here so I can see some other things I know what

some of these symbols mean but most of these other things we're going to change

in the menu one more thing on here actually we can change which is the ISO

so right now it's set to auto I'm just gonna go ahead and put that on 1600 1600

might be too aggressive once we get out there we might you know bring it down to

800 or 400 but I usually start at 1600 or even higher because when you're just

doing those test exposures to see what you have make sure things are in focus

and not streaking it's nice to have a high ISO like that okay now I'm gonna go

ahead and hit menu here and this first menu screen on a Canon all the way over

on the left the first thing in there is image quality you could also think of

that as a file format all of this top row here and these two on the bottom row

are JPEG options so right now it's set on

large JPEG for astrophotography you do not want JPEG you want raw you might

think well why not get raw plus JPEG there's really no reason to it's just

going to fill up your memory card faster and you're just gonna throw out those

JPEGs so just do raw that will just capture the proprietary RAW files for

whatever system you're using Nikon or Canon or Sony all of different raw file

endings but the astrophotography software that will show will handle all

of those I would disable any beeping or anything like that it just gets annoying

under image review you want to set this to off what is image review let me show

you a I'll go ahead and take a picture here oh it's a ten-second picture so

this is gonna be just pure white

shouldn't be said that okay anyways there we go

that little two-second review of your picture is good when you're doing like

you know regular photography but for astrophotography you really don't want

that because for one it will ruin your dark adaptation of with your eyes really

sort of blind you at night and two it will drain the battery faster three this

is a minor issue but it might raise the heat of electronics and the sensor up a

little bit and with without cooling its you really want to try to keep the

camera as as cool as possible so any anything that can raise the heat inside

the camera is bad so we're gonna turn that off image review off you can always

just hit the playback button when you're doing some testing to see the picture so

you don't need that alright let's see if there's anything in here this doesn't

really matter because it applies to the JPEG transformation I believe but I just

like to set the picture style dat neutral again I don't think

that matters colorspace I would suggest putting this in Adobe RGB I'm not sure

again if that matters but that's what I've always done long exposure noise

reduction you might think that sounds good

don't want that I always turn that off you know some astrophotographers who try

to save time might disagree with me but I think what that will do if I turn it

on is basically take a dark within the camera and apply that to the picture

that I just took but all of the workflows that I'm going to be showing

we take dark separately and apply the darks ourselves so I always just

recommend you to leave that off high ISO speed noise reduction off again I don't

know if that applies to the raw file I think what it's saying down here is that

it doesn't but let's just turn it off anyways basically any like thing you can

turn off in here you probably want disabled it off nothing in there really

matters blah blah if whoops

if you you know your memory card was pretty full you might want to take the

pictures off of it and then format the cards here starting out with a nice full

card auto-rotate this again I would recommend turning off I've had some

issues with that in processing so I don't want it to rotate my picture so

I'm going to turn that off auto power off you might want to turn that disable

that as well I'm not sure about that I'm actually just gonna leave it on but put

it up to eight minutes because I actually might want to save battery if

I'm not doing anything and I just accidentally left the camera on okay I

think we're done so gone through all the settings that matter in the menu the

main thing if you forget all that is just make sure you're set to record RAW

files if I get out of the menu here you can see because we switched it to raw

and I'm using a fairly small memory card the number of pictures we can take has

gone down and substantially but that's plenty because I'm only planning to make

me do a hundred pictures of Orion tonight and even with darks and bias and

everything we should be fine but we might almost fill the memory card once

we get all those calibration frames while I have the camera set up like this

one more thing I'd like to point out with the t6i here it's really nice is it

has this swivel screen which I can actually point up so you might think

yeah who cares but this is a huge neck saver because when the when you don't

have a screen that can point up like that and it's just fixed to the back of

the camera most of the time this is going to be pointed down at very low to

the ground so you basically have to lay down on the ground to see it and this

where you can swivel out the screen and point it

and see it like that and then this is a touchscreen is huge in terms of ease of

use with the DSLR and no computer if you control it with the computer doesn't

really matter backyard iOS is a nice program for that but if you're if you

don't want no wires you just want the DSLR there I would for getting a new one

get one that has a screen like that that comes out and you can swivel so other

than making sure I have all the equipment I'm going to use that I have

fresh batteries that I understand how to use it that the camera has the correct

settings what else do I do before I leave the house planning of course I

have a whole video on this so I'll put that as a link here but I just want to

show since I'm showing every step of this m42 process what I would do to plan

for m42 with some basic equipment it's not going to be super involved but let's

jump on the computer and I'll show you what we can do with Geo so browser to

make a plan for tonight I'm going to start with this free donation supported

web site called DSL browser if you are interested in this how to use this

website I have another video which I'll link through an annotation right here so

you can find it that's all about planning for DSO imaging sessions and I

talked a lot about this website and how to set up your profile and all of that

so if you're interested go ahead and check out that video today I'm gonna go

right here - Oh Ryan Nebula because that's what we're gonna be shooting m42

and just point out a few things on this site that helped with planning one is

that right here we can see some amateur images of it which is nice and down

there it gives us some information about how they shot it so like I can see this

person used ISO 1600 so that might give me a clue that that might be a good ISO

to use or something that Alright after looking at these

amateur images the next thing I look at appear at the top over on the right is

the hourly altitude of the object and this is for my location that I set in

here so it knows where I'm going to be shooting tonight and that's how it can

know the altitude of the object at these different times and so if I just move my

mouse over this curve I can see at around 10:30 it's a 25 degrees at 11:30

it's a 35 degrees at 12:30 past midnight it's a 40-something so one thing that

you need a little experience to be aware of is when objects will get over the

treeline for whatever site you're gonna be shooting from and that's not

something you probably know right away if you're a beginner but generally if

you're thinking tall trees 3540 degrees is about where you're gonna be looking

at but generally tall trees I'd say above 35 degrees most object or an

object will get you know past the treeline that's sort of what I

generalize that is about 3540 degrees you're gonna get past any trees and so

for this object that's around midnight tonight now you might think so should I

just not go out to like 11:30 I wouldn't advise that it's really much easier to

set up as the Sun is setting if you can if it's like a Saturday and you have all

day because especially when you're new to

this it's much easier to set things up in daylight rather than in the dark but

then I have all of this time before I can actually shoot Orion so what could I

do during that time well I could shoot a different object I know for instance

that the Pleiades m/45 is available right now so I could shoot

that until Orion comes up the other thing I could do is I could shoot my

calibration frames first because some of those take longer than others bias and

flat frames won't take very long just a few minutes to shoot but darks can take

a while so let's say you're gonna shoot a Ryan for two hours tonight you may

want an hour to of dark frames to calibrate the what we call the light

frames the actual object you're shooting so I'll talk more about calibration

frames later but just to say that this time up till midnight won't be wasted we

can shoot another object or we could shoot calibration frames but it's

helpful to think about these things before you leave the house let me scroll

down here over here is a nice little data sheet about the object so I can see

it's magnitude 4 that's pretty bright even in a light polluted area you're

gonna be able to see that through any kind of telescope it's one-and-a-half by

one degree that's the size of it and if I keep scrolling down here this is a

really useful tool built in to DSO browser where I can pick from my

different objectives here my different telescopes and tonight I'm going to be

using the Astrotech 60 millimeter refractor and I can pick from my

different cameras here I have the Z wo in there but tonight I'm gonna use a

Canon and then it gives me this nice reticule right here on top of DSS

imagery showing me the object right here and I can rotate that reticule with this

orientation slider right here so if I wanted to do a more vertical shot I can

see how it looks like that or if I wanted to do really horizontal something

like that I think I'm gonna do something like this where it's like it a little

bit of an angle this right here this bright part is

Orion and then this little part right above it is the running man nebula

alright I think that looks pretty good and so one thing that I will sometimes

do now is all take a screenshot of this

and I'll open up that screenshot in something like Photoshop but it could be

whatever image editing program you're comfortable with and I'll invert it then

it's just a little bit easier to see the star pattern I'll maybe make it

grayscale because I don't really need the colors there just to see that star

pattern really clearly and sometimes I'll also play around with curves a

little bit just to add a little bit more contrast so that those stars and the

dust is really clear so I can really see the framing now and how that's going to

look on my sensor and then I might print this out or send it to my phone so I can

look at it later when I'm doing the framing so that's about it then we're

gonna I'm going to do in the computer for this object

like I said we're keeping it pretty basic today so I'm not doing a huge

amount of planning we're doing what's called a one shot color camera OSC so I

don't have to think about filters or anything like that

and in terms of a plan I'm just going to shoot this as long as I can I think

there's gonna be some clouds coming in tonight so I might only get I don't know

an hour on it or something like that but we'll just shoot it as long as we can

and in terms of the amount of time to put

into each sub exposure I'm somewhat limited by my mount tonight and also the

fact that I'm not going to be guiding so probably can't do really long exposures

anyways so I'm gonna try 30 seconds and then just set the ISO based on what the

histogram bump looks like so I'll explain all that later when we're

actually doing it but that's my plan I can print this out or send it to myself

now so I have an idea of the framing and we're ready to go yeah we have a nice

night here in Delaware the moon is setting over here to the southwest and

Orion is rising over there to the southeast and we're about ready to get

rolling here I've already set up the IAP tron tripod as you can see and you

really when you're doing extra photography you don't want to raise this

any higher than is necessary the legs would extend and make this quite a bit

higher which makes it a little bit more comfortable to use but that's really

just for visual use so that you're at a comfortable plate height for the

eyepiece for astrophotography you want to keep center of gravity as low as

possible so this is how I have it here I'm just gonna put in this tray okay and

I'll go ahead and make sure this is level just by using a little level on my

phone here yep that's pretty good I also can check that this pin right

here is roughly pointed north because my leveler

it's part of PS align Pro which is a true dialer app also has a compass built

into the leveler so I can see that's north which is good

alright next step is I'm going to take out the mount head here and with the IAP

drawn when to fit it back into the case you have to take out this bolt and then

put it in each time and what this bolt does is it's the latitude or the sorry

the altitude adjustment all right got that bolt in there I can just put this

on to the tripod here

and right below the mount head is the screw here to attach it and secure it to

the tripod okay that's now securely on there and I'm

going to release the counterweight shaft ring like that and take off this piece

and on the back here take off the cap and there's a polar alignment scope

built into this and I often like to look through it before I turn the mount on

because once you turn the mount on you usually get a pretty glaring red light

but I like to sort of make sure I can see Polaris through the polar alignment

scope before I turn on that red light because if it's not even in the field of

view then it's hard to find Polaris with that red light on and to do this I'm

gonna have to turn on the light lighting on me for a second here so bear with me

it's going to go dark

okay now the polar alignment pull master is on there I'm going to go ahead and

install a counterweight on the Conor white shaft just like so and I'm not

sure where on the shaft this should go yet because you have to do that with the

telescope up here so you can balance it that's good enough for now

and I'm not going to turn them out on yet I'm just going to get ready here by

putting attaching my hand controller here and I've put some little figure

what they call these waterproof velcro for that just to stick on the front like

that okay ready for the scope

hey now let's go ahead and balance

alright so see how it's it's falling this way towards the counterweight I

want to get it so that it's just slightly falling to the counterweight

side but basically balanced this is called

getting a little bit east heavy not having quite perfect balance but pretty

close okay that's good

okay now I'm going to do the fine polar alignment and again I'll have to turn

off the light to do this but basically the idea here is you just tell the

software what do your axis of rotation is and

then it looks at the patterns of the stars around Polaris and you can get a

very fine polar alignment using this electronic scope and your computer but

again this is optional another way to get a fine polar

alignment is through what's called drift align which you can look up it's

basically just watching the Stars drift on your DSLR and fixing the plural in it

that way all right so I'm going to turn off the white

okay now I've done a great puller alignment with the pole master I'm gonna

go ahead and turn the mount on this mount runs off eight double-a batteries

or it can also run off 12 volt or battery a bigger battery it has a socket

here go ahead and use this to put in information here again I use PS align

Pro two for my GPS coordinates so I'm setting what's called the time and sight

in here and then I click on set zero position which just tells it it's this

counter way down pointing it Polaris position and now we're ready to go so

I'm gonna go ahead and just go to they call it select and slew in the menu here

I'm gonna go to m42 and the mount starts slowing it's going in the right

direction besides a good sign

once it gets there I'm gonna use this tell rad which is just a type of

finderscope to Center and pretty to a little bit

better before turning on the camera and doing some more framing in there all

right unfortunately I'm gonna have to turn off the light once more

okay I've centered the target using the towel rod here and then I turned on my

DSLR and it was right there on the LCD and I recognize these as the stars

around their Ryan Nebula but for a beginner you might not but then all you

have to do is just take like a 10 second exposure for instance

and take a look at it and there you see Orion right there in the middle this

framing looks pretty good you just take a look here yeah I like that sort of

going sideways here with the running man up there just see if I can see it

without all this stuff there we go maybe

I'll just push it down just a tad so

yeah I think that's good okay and I'm just gonna go ahead and pump this up to

the 30 second exposure which is my what I was hoping for just make sure I'm not

trailing the stars or anything and I'll also take a look at the histogram just

to show you how you can evaluate if you have a good exposure level it looks

super bright but that's usually okay let's zoom in on the stars here yeah

what I do

those stars look reasonably around but it's a little bit hard to tell because

we are not focused that's something I forgot to do so let's go ahead and focus

use a live view

get a zoom in

I'm going to find my focus here and you can see when I go that way star is

getting bigger we're seeing sort of the pattern there when I go this way

eventually it gets bigger again but really out of focus there so what I'm

going for is trying to get that star as small as possible

and the other thing I can try here is I have a bad enough mask this star might

not be bright enough but let's go ahead and try it okay it's just bright enough

that I can probably do this might be hard to see on your screen though there

right there is focus I can see the pattern of the badenov mask and you just

want to get that central spike in the middle see that's out that's out that

way that looks good just to test that I'm gonna go ahead and take a 6 second

exposure with the bad nut mask on

yep that looks good okay zoom in further so you can see what I'm seeing here see

that so that's good focus with the badenov mask that central spike is right

in between the other two and I'll go ahead and take it off now and do what I

was doing before which is taking a 30 second exposure see if our stars are

trailing and if this is a good exposure level

all right zoom in on this guy doing that sorry

those stars do not look like they're trailing at all but I have a little bit

of a streak that's just because I was hitting the trigger but stars look good

I'll check the level now which I just get by hitting info here a couple times

to zoom out first

there's our histogram it's actually a little bit too far over we only want it

about a quarter to a third of the way over so I'm going to turn down my ISO

and try this again turn it down to 800

check it again there we go so a quarter to a third of the way over it looks good

let's check our stars again the stars look perfect so we're ready to go so

last step here so I'm going to take my intervalometer here

and just make sure it's set right 31 seconds that gives a one-second gap

between them I'm gonna take let's say

try for 50 shots I don't know if won't get that before it hits the trees but

we'll try it

go ahead and get out a live view here close this up and start alright now

we're gonna do the calibration frames I'm gonna start by taking my flats here

you can see I have a LED panel that I use and I also have this little cap

diffuser but you can just use like a white t-shirt that works fine and you

don't need the white LED panel either you could this is just what's called a

tracing panel I got an Amazon but you could instead use like a iPad or a

laptop screen turn to white I'm gonna put that on top here and that's about it

in terms of setup just you just want something white and diffuse and filling

the entire field of the scope and so you can either use a screen like this on top

or you could shoot sky flats just pointing at the sky with some kind of

diffusion or even just like a white wall that's evenly lit so let's look at the

back of the camera here so we can see the settings for flats basically I just

use the same ISO that I gonna use for my lights and then I just sort of

experiment with different exposure length settings here or it also called

shutter speed on a DSLR until my flat is about half the way over doesn't have to

really be quite half because I won't get into it but this is a JPEG histogram

it's not the raw histogram so really if you under shoot a little bit that that's

just fine and some people do this with aperture

priority that's another option for taking flats and I'm gonna take about 50

of them okay for the next group of calibration frames we want the front

lens cap on so I'm just going to put that

here because these are both done in darkness and I really all you have to do

is just put that lens cap on you also want to make sure that you're at around

the same temperature as where what you're shooting your lights at so we've

been out here a while I've let the the scope and the camera cool down it's

mostly that the sensor that you're worried about being at the same

temperature so let's start with bias frames those are really easy and quick

to do we'll look at the camera here and all we have to do on the camera is turn

the shutter speed all the way up by that I mean the fastest that it can go so in

this DSLR that's one four thousandths of a second it might be different on your

DSLR it might be one eight thousandths of a second but the point here is you

just want a very very short exposure and this is going to reveal what's called

the fixed pattern noise on the camera sensor I'm gonna use my intervalometer

here to take a bunch of them with bias frames I usually take at least a hundred

if not more to really get a nice idea of that noise that's fixed to the sensor

and finding those banding patterns and things like that you really want to a

lot to average together so I'm going to type in a hundred here and let it go

okay and for our last calibration frames the only thing we have to change here is

the shutter speed these are darks and we're just gonna change the shutter

speed to what the same shutter speed that we're gonna use for our lights in

which in my case I've already decided on 30 seconds so I'm going to change it to

30 seconds here and the number of darks are gonna take right it's always more

the better but usually you don't have to take you no more than 30 or 50 or

something like that with 30 second darks I might as well take a bunch but if you

were doing like five minutes of exposures that could take a long time so

usually around twenty or thirty is is fine and the only other thing with darks

is you just want to try to match that temperature as well as you can so if you

think that it's gonna keep dropping in temperature you would want to do them

closer to when you shoot the lights so that that temperature stays stable all

right I'm gonna let this go and take about thirty okay first thing you're

gonna want to do after you've had a successful night of imaging is get all

of your files off of your DSLR and on to your computer and I like to put

everything in one folder so you can see I've started a folder here for this

project and then I organized things like this I put my bias my darks my flats my

lights all into their own folders and then I have a new folder for processing

files and so I've already taken the files off of the camera and put them

into the appropriate folders here but I think it's interesting to look at what

these files look like on their own before we do anything with them so let's

take a look if you have any kind of RAW processing software on your computer you

should be able to just double click one of these to open it up like Adobe

products or a raw table or dark table or there's a bunch of GIMP there's a

two different programs you can use to look at these I'm just going to use

whatever comes up here probably Photoshop look at these different files

okay so this is a Photoshop Camera Raw Dobby Camera Raw it recognizes the DSLR

that this was shot with which was again a t6i it recognizes that this it was

shot at 1/4 thousandths of a second so that's a bias frame iso 800 and all i

want to show you here is what this looks like in this state it doesn't look like

much at all but if I really just stretch the exposure here you can see that there

is a lot of noise here and also these sort of alternating dark and bright

lines that is the fixed pattern noise on the sensor and we want to subtract that

out of our flats especially it would also be included in the dark frames so

the point is really to calibrate your flats properly because your darks are

going to be exposed for your lights while these bias frames can be used to

take this pattern noise out of my flats so I'm not adding noise when I divide

the flats out okay so that's what those look like let's go ahead and open up a

dark it's gonna look pretty similar I'll stretch it here with this little

exposure agai and like I said it looks very similar if we really stretch it out

these bright pixels are hot pixels you can see that it has that same fixed

pattern noise the horizontal banding of the bias frame and this is to handle

dark current noise in our lights so since I was using an uncooled camera

there's going to be some heat buildup on the sensor and this is to calibrate that

out and let's look at a light frame so sorry

flat so this is the last calibration frame and it's really important a lot of

people forget to shoot them let me just mess around with this a

little bit to sort of show you what this does okay so might be hard to see

let me just accentuate it a little bit further

I don't know if that helps what this does is it's trying to model I've been

getting in the system so I've been getting is where the corners are darker

than the middle because they're not receiving as much light and so this

looks like a pretty flat frame already I was trying to accentuate there we go

that you can see once we stack them it'll look a little bit more like this

probably where the middle part is getting more light in the corners which

are darker and so that's what this is trying to model it can also if there's

any dust or what we call dust and donuts in your system like dust falling

anywhere in the optical train you can also model those and divide those out so

flats are very important to take this is an example of what one looks like and

not much else to say about that so I mean I have it and cancel open up a

light and lights are your pictures of the actual object and I think we did

about 70 of them here at 30 seconds each and so this is what a single light frame

looks like this is with an auto stretch what's called a gamma curve applied but

so without anything done to it this is what a light frame looks like if I play

around with these sliders a little bit let me bring up the exposure bring down

the black level bring down the contrast bring down the highlights a little bit

bring up the clarity change the temperature just a little bit here

this is about how much detail we get from a single exposure and it's very

hard to see but you can see in a single exposure here we do get some of the

outer nebulosity but that will show up a lot more when we stack you can see in a

single exposure we don't see much of the running man here but again after we

stack 70 of these a lot of that will become clear because right now it's lost

in the noise and it's also lost in the light pollution gradient here but you

can see in a single exposure we do get some nice detail and the other thing we

would do when looking through these single exposures is reviewing that each

one is doesn't have any mistakes in it like that the stars are reasonably round

and in focus in this light after I've messed with a little bit here you can

see the vignette in on the corners so again that's what the flats are supposed

to take out so we can use more of the frame all right that's it

I'm gonna cancel out of that so that's our four different frames once we have

these all sorted like this on our computer we can move on to the next step

in processing which is calibrating our lights stacking our lights after

registering them to each other using the Stars to register and we're gonna look

at some different processing methods to do that we can try deep sky stacker and

Photoshop or GIMP and then we can also look at it how to do it in pix insight

okay here we go with deep-sky stacker this program is

Windows only but it is free and what it does is it registers your light frames

it calibrates them we have darks flats and bias files and

it stacks all of that together and can do things like Sigma clipping to get rid

of things that are abnormal like hot pixels and and just airplane streaks and

all that kind of stuff and it's a very easy to use program once

you get the hang of it it does this one thing very well which

is stacking and doesn't do much else so let's look at it we're just gonna use

the basic features of it here we start over here in the upper left hand corner

by clicking open picture files I'm gonna click on that and find the light frames

for the object that I'm working with so if you've already organized like I have

here it's pretty easy you just go into the m42 folder click on the lights

folder and there's all the files if on your computer you are not seeing your

files for some reason just make sure that down here it's not set to something

weird like JPEG only or picture files it's set to just all files and then you

should see all of your RAW files I'm just gonna click on one and then press

ctrl-a to select them all and then click open okay what I can do here in deep sky

stacker is click on one I'm just gonna click on the first one and it gives me a

nice little preview here of the file we're not seeing much other than the

really bright stars here if we zoom in we can see that there are dimmer stars

as well but if I wanted to brighten this picture up a bit this is just for

preview purposes I can go up here to the upper right and drag this middle slider

in a bit to the left and it brightens up the picture some and I can

some of the dimmer stars now which is helpful for evaluating focus and also

how much elongation of the stars there are and in every frame deep-sky stacker

can do some stuff with evaluating the Stars for you but if you want this more

manual control it's here for you you can zoom in you can look at the pictures you

can go through them one by one takes a second for it to load each picture you

can zoom in on this one and I can decide is this a frame that I want to keep or

do I want to get rid of it and I'm not gonna show that whole

process but I'll just show you an example of a frame that you would not

want to include let me go all the way down to the bottom here and I remember

at the end of the night my last frame I must have hit the tripod because there's

like a little jitter in it let me zoom in on this okay and you see that that's

on all the stars that little jitter on all the stars that's from knocking

something or stepping too hard or whatever and it can also happen from

wind but basically we wouldn't want to include that frame so how do we not

include this frame what we want to do is we first want to check all so I'm going

to go over here and click check all and then I'm going to just uncheck that last

one that one I don't want to include just by clicking its little checkbox

here to uncheck it okay so we have 71 of 72 light frames checked now we're gonna

go ahead and add our dark frames click on dark files over here I'm gonna hit

control a to select all my darks those

if we look at one of those I'm just going to click on one here it doesn't

look like much if we really stretch it

still doesn't look like much

but that's what darks are they're basically just correcting for hot pixels

and thermal noise things like that let's go ahead and add our flat files control

a to select all of these click open brings in our flats let me stretch this

a little bit so you can see what it looks like too much there we go

so you can see that it gets a little bit darker towards the corners here that's

representing the vignetting I don't know how clearly you can see that but that's

our flat frames and last our bias frames let's add these control a to select them

and we have 100 bias frames in here let's see if we can see anything in the

bias it's sort of hard to see anything but basically that represents the fixed

pattern noise on the sensor and it can get rid of horizontal and vertical

banding problems that it is common with DSLRs okay so we have all of this added

now and remember with that last light frame I unchecked it looks good if we

want we can look at the raw settings which are down here under options raw

settings and these are the same as the last time I set them up I just use this

default Bayer matrix interpolation I've always used camera white balance because

I'm always careful to set that if you didn't just uncheck that to not use it

at all I always set the black point to zero

which helps with calibration I believe and if you change any of these just

remember to click apply before you click ok next thing I'm going to do is over

here on the left hand side under register

cheering and stacking and click on register checked pictures it brings up

your register settings these will be whatever you last set them at so if you

want it to automatically detect and remove hot pixels make sure just to

check that I'm going to do that if you've already registered the pictures

you can use this option right above there but I haven't registered these

together yet I mean putting them all on the same place so the Stars match up so

I'm gonna leave that unchecked I want to check stack after registering cuz I do

want that to happen and right here it says select the best percentage pictures

and stack them you can change this to whatever you want basically it just

assigns a score to each picture based on how round the stars are and if you only

wanted to include like the best 50% or 80% you can set that right here if you

want to include everything just put in a hundred percent I'm gonna put in 97

percent because maybe there's one that I didn't catch that it could throw out

next thing I do is I go over here to the Advanced tab and by default it sets this

star detection threshold to 10 percent you may not need to change this though

to get a good number of stars if you're below let's say 50 stars you probably

want to change the detection if you're above a thousand stars you might also

want to change that detection because they might be picking up hot pixels and

things like that so I'm gonna go ahead and click on compute the number of

detected stars it looks at the first light frame and sees how many stars it

can find looks like I have plenty here it found almost 300 so that's fine I

could just leave this alone at 10 percent but if I wanted to speed this up

a little bit I might take this down to 20 percent I'll compute again

and now it's down to 177 stars so it's just fewer stars to match against

usually works a little bit faster and better so I'm going to leave it at that

I'm going to go ahead and click on this reduce the noise by using a median

filter and then I'm gonna click on recommended settings and basically you

can just step through this and any time where it's highlighted in blue here you

can read what it says if you were using a modded DSLR well I'm not so I'm going

to ignore that if you are processing narrowband images I'm not so I'm going

to ignore that one and then you just go through each one and if it's something

that you haven't done you can just click on that and it will put that into your

recommended settings I'm using Sigma clipping I'm using bilinear d bearing

and blah blah blah so you can go through there make sure you have all the

recommended settings click OK if you want to go into stacking parameters and

look at these this has much more detail I'm not going to go into all this right

now because this isn't a video about deep sky stacker it's sort of an

overview of all the processing so this would take too long but there are other

videos online so if you're interested you can learn about all these different

settings in here this is good enough though we're gonna go ahead and click OK

and it gives us a nice summary here of everything we're gonna be stacking 72

light frames with offset or bias dark and flats specifically a hundred bias 25

darks and 29 flats the total exposure is 38 minutes 24 seconds all looks good I'm

gonna go ahead and click OK to start the process and off it goes it starts by

stacking together all of your bias or offset frames into a master bias it then

does the same thing for darks and flats it then calibrates all your individual

light frames with those master calibration frames and then registers

and stacks your light frames into your final single integrated image which you

can then preview here in deep sky stacker but usually you just save it off

and we move on to Photoshop or GIMP so I'm gonna speed up this part of the

video because it's gonna take at least 10 minutes probably more like 15 or 20

and then we'll I'll show you saving out of deep sky stacker when this is all

done

okay so what it's doing right now is it's saving the autosave dot TIFF file

to my lights folder this is important this is a 32-bit TIFF file that you can

consider your master stack Photoshop can actually read a 32-bit TIFF file so you

could bring it right into the autosave dot TIFF right into Photoshop not all

features in Photoshop are 32-bit so you might have to eventually convert it to a

16-bit file if you're going to be working with GIMP it probably can't even

open that 32-bit file so we're gonna have to first save the picture to file

which is over here on the left hand side under processing and save it as an

uncompressed 16-bit TIFF one thing that's a little bit confusing here about

deepskystacker is it's making the final picture right here on screen and there's

a bunch of settings we could change right here and deep-sky stacker but it's

not really meant as a processing program it's just a stacking program so really

there's not much point in doing much here because we're not going to save

these changes anyways so I'm just going to leave all that alone and go over here

to where it says save picture to file and I'll just save it here to my desktop

to my m42 folder and I'll call it stack dot TIFF and I mean to say compression

none and I want to just leave this option that says embed adjustments in

the saved image but do not apply them checked so basically just exactly how it

was and click Save okay now that I have a stacked image out of deep sky stacker

I have moved on to Photoshop here everything I'm gonna show today it

really shouldn't matter which version of Photoshop you have I'm just using the

latest here but I've used the previous version cs6 cs5 cs4 they all work pretty

much the same and we're gonna start by opening up our stacked TIFF out of deep

sky stacker so we're gonna go up here to the file menu and choose open and find

it here on the computer and open it up and it looks something like that

it looks like not very impressive right like we didn't capture much it looks

worse than maybe even just the individual files at this point but this

is actually exactly what we want what we took out of deep sky stacker is the

linear master so basically linear it means the same thing is unstretched

because we want to do the stretching here in Photoshop the other thing I'll

point out is that I saved this as a 16-bit TIFF and we can double check that

right here by going to image mode and see that this is an RGB color and that

it's 16 bits per channel if i zoom in on the center here it is interesting to see

that there's a lot of fine detail right in the core of Orion there even in this

sort of quasi linear state what that means is that once we get further into

processing this is going to get completely blown out to keep the rest

you know to bring up the rest of the picture but we don't want to lose that

we're gonna bring it in later so the first thing that I always do in

Photoshop here is I duplicate this later a couple times and in Photoshop that's

easy to do that you just right-click or control-click if you're on a laptop and

choose duplicate layer and you can call it something if you want I'm just going

to call mine first stretch and as long as we do that first

and we keep this background layer as it is then we're good because we can keep

duplicating off the background layer as needed so with this first stretch layer

selected I'm going to go up here to image go down to adjustments and go to

levels since we're going to be coming back to this a few times it's good to

learn the keyboard shortcut which in this case is command L on Mac or ctrl L

on Windows and here's our levels adjustment this is what you're going to

use to first apply a little bit of stretch to this and you can see that the

histogram peak here is very compressed and what we want to do is sort of spread

it out and keep moving it off the left-hand side here and then bringing it

back to the left-hand side and the way we do that is we take this middle slider

and we move it over here to the left

towards where the end of the peak is there and you can see as we do that and

zoom in again we get a lot more detail coming up here in the Orion Nebula and a

lot more stars start to appear now we want to do this in a bunch of successive

times we don't want to just sort of do it all at once so I'm just actually

going to sort of do mid like that and say okay and then I'm just going to keep

doing that press command I'll bring it up a little bit more and just slowly

stretch it out like this now eventually when the sky background

gets quite bright and we're sort of losing in a detail that we're bringing

in what I like to do is take this shadow slider this one over here on the left

and drag that one to the edge right here and it's going to sort of look like

you're you know resetting everything you just did

but you really are you really have applied some stretch here just to prove

the point to you if I turn off this first stretch with a little eyeball

indicator over here in the layers you can see we've done a fair amount of

stretching you can see m-43 is coming in right there

the arms of Orion are coming in okay but we're going to keep going with this

stretch so I'm just going to press command L one more time here I'm gonna

stretch this again press command L again stretch it a little bit more command L

and then I'm gonna bring this shadow slider over again

and I like to just keep looking at what it's doing and you can see that these

the nebula is getting more and more sort of in focus we can see more of it and we

can see this Dark Nebula coming in here now it's pretty cool

but I'm just going to keep going with this just a couple more times bring the

the the left-hand slider over to sort of the edge of these histogram peaks and

bring this one in a little bit okay at this point this is stretched enough I

can start seeing that Outernet velocity out here on the Orion Nebula and the

fainter running man is also coming into view and what is clear at this point is

that we have a fairly regular light pollution gradient where it's darker up

here at the top and brighter down here at the bottom and there are some plugins

that are really good at dealing with this there's one called I think Astro

flat Pro and there's another one called gradient exterminator but I'm not going

to show those partly because they both cost about thirty to fifty dollars so

I'm not gonna make you go buy something right away I'll show you a way to do it

just with Photoshop stools here it's not quite as effective as those plugins but

it works okay so what we're doing here is we want to remove this sky gradient

the light pollution is coming from the bottom of the frame here so that's why

it's brighter at the bottom and then the other thing you'll see here is that it's

it's fairly red that's because of when light pollution hits the atmosphere it

creates this sort of reddish sky glow if you're in a very dark place you might

see a more greenish sky glow but in light polluted place without any kind of

light pollution filter your print images will probably come back fair

redish like this in any case what we want to do is want to subtract it out of

the picture or leaving us just with a dark night sky and the stars and the

nebula so first thing we're to do is we're going to go ahead and copy this

layer actually you know let's duplicate it so you know right-click choose

duplicate and I'm gonna call this my background removal layer okay and then

I'm gonna copy it so in newer versions of Photoshop you just go edit copy and

that copies the layer you have selected if you have an older version of

Photoshop you first have to select this just do command a to make a selection

and then you'll be able to edit copy then go ahead and do file new and it

should put in here for the width and height whatever the dimensions of are

the thing that you just put on the clipboard so that's good we can call

this background and go ahead and paste it in over here in the layers panel we

don't actually need this white background layer so I'm just going to

delete it and what we want to do with this is completely get rid of all of the

stars and the nebula because we're just trying to model the background so we can

come back here and remove the background so to do that first I'm gonna to get rid

of the stars the way to do that is through a filter so if you go up here to

the menus at the top and go to the filter menu and go down to noise and

then choose from the noise menu dust and scratches and you can see I've already

set mine here to something that works but basically you're just going to take

these two sliders and move them around so that for your picture whatever the

radius and threshold are set to it's getting rid of all of the stars now if

you find that like here it's not getting rid of the halo of that

brightest star that's okay because we can take care of that the same way that

we took care of the nebula here but what you do want to do is set this so that

for all these medium and small stars it's just completely blurring those out

into the background this looks good for this particular setup I'm at 58

pixel radius and three levels under threshold I'm gonna click OK to apply

that takes a second and by the way don't worry about if it's doing something

weird along the edges or the corners cuz later on and processing we're gonna crop

those out anyways that's normal what we're gonna do now though is we want to

get rid of this the remnant of the nebula here so I'm going to grab was it

called Spot Healing Brush tool if you don't have spot healing brush tool in

your version of Photoshop Healing Brush tool st. does the same thing and my

version it looks sort of like a little band-aid

and what I want to do with this is I want to set the size to be fairly big so

I can just do this quickly so I'm going to set mine to around 500 pixels it

doesn't have to be a particularly hard brush I could set that to a low hardness

and I want to make sure that it's set to the content-aware

type and then I'm just going to brush over anywhere that there is nebula and

you might have to do it in a couple passes here but it should go pretty

quick you'll be able to get rid of

all of that nebulosity that's in the background there

and I usually start out sort of broad with this and then fix smaller little

issues but usually don't really have to change the brush size I just sort of

okay that looks good enough to me basically this is what in pix inside we

would call creating a background model and this is how you do it in Photoshop

so I'm gonna go ahead and save that just press command s ctrl s on Windows and

it's saving as background PSD that's fine then I'm going to go back to my

main picture here and with this background removal layer selected I'm

gonna go up here to image go down to apply image and for the source

I want background for the channel RGB that's fine for blending I want to go

down to subtract

and then you'll probably find that you have an offset here of zero try

different numbers there until you basically get a fairly grayish

appearance the colors aren't going to be perfect yet but what you want to do is

sort of get this mid gray sky so for my camera here that was an offset of 50 you

see that if I put it at 30 that's a little too dark 20 darker still zero is

obviously too dark I've lost a lot of that nebulosity that I brought up

previously in the stretch so 50 looks good to me I can see a lot of the detail

that I brought out there and the stretch the other thing you can try here is you

can change the opacity from a hundred to something lower so for instance 90 and

see if it's still removing the background well enough with a lower

opacity setting 80 see now at 80 I'm seeing a lot of that red come back so

I'm gonna set it to 90 here and the reason I'm seeing anything as I'm

changing these numbers is cuz preview is turned on if when you're changing these

are not seeing anything just make sure that right there you have preview turned

on all right I'm gonna go ahead and click OK and just doing those couple

steps stretching and removing the background have already made the picture

a lot better we can see what the background removal did by just turning

off the visibility of it over here in the layers panel so that was before with

that red background and had a strong gradient top to bottom and here's after

removing it

okay so next what I can do is continue working basically on setting the levels

of this image we can see now that there is a lot of interesting detail in here

there's a lot of cool dark nebulae there and even there there's m-43 this little

piece up here that was not visible before you get this really nice blue and

red it's a little bit dim at this point a little bit unsaturated the running

man's barely showing up the challenge here is we want to continue stretching

this continue bringing out the nebula but we don't want the stars to get too

big so there's different ways we can do this we can attack this with masks but

usually I just like to do a little bit of stretching before I go to masks but

since this is a good sort of starting place I'm gonna duplicate again so I'm

gonna do duplicate layer and I'm going to call this one experiment alright and

for my experiment I'm gonna go ahead and instead of going to image adjustments

levels I'm you know this time go to curves and curves is just slightly

different from levels in addition to changing the brightness you can go into

the individual color channels which is useful and change the levels that way

and then it also just is a different feel since it changes things instead of

sort of more uniformly it puts a curve in there so it's you can see that with

this curve it's gonna bring these tones right here up

other than these ones and more than these ones when you whenever you take a

point in the middle and bring it out like this that's going to always sort of

add contrast if you take another point and you bring it down like that and make

this sort of S shape that's going to really add contrast because basically

you're saying bring the background sky level down and bring the Stars and the

nebula up so that's really going to create a lot of contrast in the image

and it already looks a lot better but we have to be careful with this because if

I turn the preview off and on here you can see we're losing a lot of detail

there in the middle but the nice thing is if I turn the preview off and on and

we look up here we're gaining detail up there by increasing the contrast so

there's a lot of trade-offs when you're processing astrophotography especially

objects like there Ryan Nebula where it has a very bright core and much dimmer

outer parts and the way that I typically deal with this is instead of trying to

create a really nicely feathered mask in Photoshop I'm just going to go ahead and

accept that the bright the center part is gonna get really too bright here and

then I'm going to come back in to this background layer that I've saved told me

to show you that again and I'm going to restore detail using my original picture

this is sometimes called an HDR approach a high dynamic range approach one thing

that a lot of people think is that you need you know different lengths pictures

10-second 30 second two minutes five minutes to make an HDR approach image

you can actually do it with all the same sub exposure lengths and it often works

out pretty well with this particular mount I wasn't going to be able to go

too five minute sub exposures anyways if I

could though it would make that my job a lot easier because I would see a lot

more of this faint detail out here but in any case I'm getting sort of off

topic what we are doing here with this experiment is just sort of seeing how

much we captured so let me go back into that curves and I'm just going to do a

really really dramatic curve here just by bringing this point all the way to

the edge and then taking this shadow point and dropping it down there okay

and this is useful just because we can see that we did capture some of this

outer nebulosity but to bring it out from the sky background it's going to be

pretty noisy right see all that noise when we really take this faint part and

stretch it like this but it might be worth it for the image let's zoom all

the way out and see what it looks like like that looks pretty cool I think I

like how that adds something to the image and it really to see more of the

extent of the running man I think and how they're even sort of connected here

really adds a lot to so how do we incorporate this let me go ahead and

just accept this curves and say ok and I'm going to do that curves again and

bring my black point back over say okay

and the problem here is a couple things one is that we made our stars really

ugly it made them really bloated and bright white and the other thing is

obviously it completely blew up the core

and it brought up some detail which I'm not sure is really worthy at because

it's just so faint a lot of people try to preserve this dust but remember this

is only thirty minutes of total exposure so I probably would just clip that down

into the sky because it really is never going to add much to the picture but

maybe I do want to keep some of this outer part of the nebula city and I like

how that looks over there too so how do I do that well first thing is I want to

get rid of the stars in this image so I'm just going to go ahead and do the

same thing we did before which is go to filter noise dust and scratches but if I

just leave it on that setting you can see that it completely blurs the the

nebulosity we can see where it is but it doesn't look very good we don't retain

any of that sharpness in it so what I want to do is I want to bring this

threshold level way up here to a point where it is basically capturing the star

cores

I'm just gonna play around with these a little bit but leaving this fine detail

in the nebula alone okay so I'm gonna go ahead and apply that and if we have some

Star Wars that are not like that really really bright star right there is still

in there that's fine we can clone stamp that out later don't worry about it but

all these major large stars all that's left is a little bit of the halo around

them that's good okay I'm gonna go ahead and click okay and

then we're going to do that a couple more times each time bringing down that

dust and scratches filter values a little bit so I'm going to go back to

noise dust and scratches bring down the radius and the threshold and you'll see

that each time we do that it cuts a little bit more of that stellar halo

away leaving though these fine details in the nebula

go back filter and noise dust and scratches you can hear my computer fan

going here because this is a fairly intensive process it's doing bring it

down this time to 25 bring the threshold down to like 50 filter noise dust and

scratches bring it down to 19 and the threshold down to 30 something and I'm

not picking particular values here I'm just sort of doing this by eye and

bringing it down you know about 10 and 15 each time and you can see at this

point we've gotten rid of most of the stars in the background but the nebula

still looks pretty detailed I'm gonna do it one more time here there may be two

more times

mm hmm maybe not actually you see

yeah at a certain point you get diminishing returns here I'm gonna

cancel that one all right so we still have a few problems here though

a few areas where the star halos have been left so to get rid of those we're

just going to use our Spot Healing Brush that we used before but this time we

don't want it to be much bigger than the star halo itself

and basically I'm just getting rid of these brighter star halos

okay and it doesn't look so good but the point of this was really just to

get some of this outer nebulosity we're going to come back in and restore detail

to everything in here and in here where we lost some detail but it's really just

to get this outer nebulosity and then restore it within a picture where we

have the smaller stars and the way we're going to do that just as a test here let

me go ahead and move the experiment layer down one and I'm gonna go ahead

and just take this and actually before I do that let me fix the background here

cuz this is very reddish and we were really seeing that gradient again so let

me just go ahead and go back into image apply image and yeah let's subtract

again this time I'll do an opacity of say 70 looks good and now I'll just

reset my black point image adjustments curves take this one and bring it over

here okay so that's good it looks pretty good for like the outer and a velocity

here and the sky background level is good again let me just check this

background removal layer that's fine well actually let me just move the dark

I realized that we haven't done much with the stretching here because this

was at an earlier stage so let me just duplicate this one more time I'm gonna

call it initial I'll rename my experiment outer

Neb okay with my initial I want to go ahead and open up curves and reset the

black point here and also just bring it up a little bit something like that I

don't want to stretch this too far so I want good stars okay but that looks

pretty good and I'm gonna take that initial and I'm actually going to move

it above the outer nab layer just drag it up and turn it to the screen blend

mode and what that does is it basically let me show you before and after so

here's normal blend mode where it's just showing what's on top here at 100%

opacity if I change it to screen blend mode any of the darker parts in this

image go to a lower opacity in the outer Neb but can come through now by doing

that it brought the sort of the overall black point back up to a light gray so I

would want to get once again open up curves and apply it but remember every

time we've been doing curves up to this point it's been just applying to the one

layer we don't want to do that on a layer that we've blended

because that's going to screw things up so instead we want to add what's called

an adjustment layer I think Photoshop added these in like

cs3 or cs4 and so up here right above the layers panel just choose adjustments

click on the curves adjustment layer and it comes in here and basically then it

just applies to everything below it so if you have any blended layers it's also

going to apply to the ones below and I'm just going to reset my black point here

a little bit there okay so this is looking pretty cool now but we have one

big problem which is our blown out core and m43 is even blown out now so to do

deal with that we need to paste in another stretch I'm

going to go back here to my background layer and I'm going to duplicate it

and I'm gonna call that duplicate layer core and I'm gonna take that core and

I'm going to bring it back up all the way above the curves here and let's just

apply a light stretch to this command L

just the same way we were doing it before and then I'll just do a little

curves here I'm gonna zoom in I want to see you know fair amount of detail here

in m43 and in the core but also I don't want it so dim that it's just gonna look

fake yeah I think something like that of course this is very red because we

haven't subtracted that background let so let me do that image apply image

subtract at 70% that's fine okay okay so now we have just a nice

little layer that's really just focusing on the core here and what we're gonna do

is basically paint that back into our crazy blown out version now the problem

is another problem that we have now is that our crazy blown out version is way

noisier than our core version here which we haven't stretched as much because

we're bringing out that really really faint detail here in our crazy stretched

version so what I like to do to sort of make them mesh a little bit at this

point is apply some noise to this one I know that sounds crazy to

apply noise but basically it's just going to help us mesh these two better

some of these things that I'm talking about are not necessarily best practices

they're really just what we're doing because we only have 40 minutes of data

here to make it look as good as it can so anyways go up here to filter we're

gonna go down to noise and click add noise and basically just play around

with this amount until it looks somewhat like that layer below unfortunately we

can't see that layer below while we're doing this but I think something around

7% looks about right there okay you know fly that add it noise and then I'm gonna

start I'm gonna go back here and just sort of see where do I have to paint

this in and it's basically this whole area right there and that right there

and I'm gonna start by adding a layer mask which is down here at the bottom of

the layers panel it's just a little white square with a black circle in it

and I'm gonna click that and it adds a layer mask to this core layer right now

it's completely white meaning that this is completely showing but if I fill that