My 2021 Astrophotography Image Processing Tutorial!

hi everyone trevor jones from astro backyard here and today i have a long overdue image processing tutorial for you in my last video i mentioned how i would walk you through the steps i took to create my best astrophotography image ever and that's what we're going to do in this video i wanted to say right out of the gate though that there's a few pieces of software that you'll need if you want to follow along deep sky stacker adobe photoshop and pixen site so i understand if this is more of an intermediate to advanced level processing tutorial and you don't have that software and you're not ready to take it on yet just want to get that out of the way also this data was captured with a monochrome astronomy camera through narrow band filters so it's a different process than say a color dslr and one shot color so hopefully you enjoy this tutorial you learn a few things and stick to the very end to see the final results here we go so we're going to take a look at the data i collected on the pelican nebula and stack that in deep sky stacker to start deep sky stocker is a free stacking software to calibrate and integrate your image exposures it may not be the best tool but it's the one that i still currently use astropixel processor is another great one to use that one's a paid one but we'll go through deep sky stacker for now so you can see how i created my final image so i'm in deep sky stacker 4.2.6 which is the latest version currently and that is pretty recent i think i downloaded about two weeks ago the latest version so i've got my acquisition data here pelican nebula in h a and o three so it was over two nights that i captured these images so i'll select the h a files first open those up and then i'm gonna add the dark frames as well i only used lights and darks no flats or bias frames for this project let's get the darks in there so 300 seconds long at -16 degrees celsius so here we go an important thing to notice here is the score that deep sky stacker has associated with these images you can register your images and it runs through the register process so it lines them all up but doesn't actually stack them and then you can actually see the scores and take away the ones with a low score because those stars are either going to be out of focus or moving and then just use your best image frames that's that's good practice i believe all of them are pretty good here what i usually do is look at the worst one so the score of 111 i'm just going to turn up the brightness here very dim linear exposures here it's almost completely black so 111 and then i compare it to the best one here of 209 yeah there's not that much of a difference at least visually so i'm going to go ahead and stack all of them so that's night one and a lot of people ask me about this how to stack data from multiple nights in deep sky stacker it's very very easy of course you want to make sure that your image is framed up the same way through both both nights or you're gonna have a real problem getting them to align things are framed up pretty good here and there's a little bit of overlappage but you'll see what i mean so here's knight one in the main group i'm just going to go to the next tab group one and then add the second knights and we're just doing the h a here not the o3 so i'm going to go to knight 2 and select the h a frames here so i'll open those and again you see those scores they're pre-populated because i've already stacked these images normally you'll have to register your images before you see those scores appear all pretty good we're getting higher scores than we did the night before i'm wondering if those the focus was just a little bit better on the second night or maybe the the transparency was better either way those all look great i'm just gonna add the dark frames in i'm not even sure if i collected new darks for this night oh it looks like i did about 10. so they're the same temperature and it says 03 there because that's the filter that was in there when i took the darks but of course the lens cap was on so it doesn't matter which filter is just a dark frame so there you go i've got my two nights worth of images some settings that you want to pay attention to here in this options dialog box here raw fits ddp settings one thing you want to make sure is that if you've been stacking one shot color data you might have this box checked monochrome 16-bit fits are raw files created by dslr or color ccd camera when i use a one-shot color camera or my dslr that box is checked you want to make sure that is unchecked if you're using a mono chrome camera like i am here that's the case so bi-linear interpolation works well on this you can experiment with the ahd if you don't like the result that deep sky stacker spits out here but these are the settings i'm using for now and we're going to keep that and just hit apply for good measure and then we're going to check all so all the lights and darks are checked and we're going to go into stack checked pictures here we go we can see that where it's going to say that we should be using bias and flat frames slap on the wrist there and we're going to get three hours of total exposure in ha it's worth looking into the stacking parameters i am going to drizzle these images two times drizzle so it's going to make the image twice the size and i believe that drizzle is only effective if you dithered your image during the image acquisition stage but if you're auto guiding chances are you are gathering your images that simple step to create a better image so none of the other settings are changed in here from the default kappa sigma clipping it's great because i i am using the latest version of dpci stacker just reset all the default settings so you don't have to worry about me changing any subtle details there okay so we're going to stack this image of three hours of the pelican nebula and ha and then i'm going to go through and do o3 next the h alpha exposures are stacked now and the the final image is nothing to look at right now or just basically a black image with a couple of white dots now here is where it gets interesting so i've been playing with pixen site the paid software because it was just too powerful to ignore for this long so i have been using pixen site for some very selective uh processes of my astrophotography images and now i do have my premium photography processing guide i'll leave a link in the description for that but there is no pixel sight in that guide because it is still so new to me i'm definitely not in a position to be teaching others about it when i'm still learning that software myself i feel very comfortable with photoshop but pixensight is still new but i will show you the the new techniques i've been using largely thanks to my friend jeff horn who showed me a lot of great tips we sat down for an afternoon and really explored pixon site so the first thing i'm going to do here is just pull up this stacked image that i just did so it is called autosave.tiff and it's in this folder 518 pelican nebula acquisition data okay here is the stacked h alpha linear file again that black file but this is like this is the funnest part by far of the entire image processing stage is clicking the auto stretch button and it's right here that little nuclear symbol and there you go look at that image so that's one click this is just an auto stretch preview to show you the data that's in your image but it's handy to have that one click stretch as opposed to pulling at it in photoshop as i normally would to get a preview for the image so we haven't changed it yet but we do have a preview showing that yes this data looks mouth-watering so i'm gonna go back into deep sky stacker and do the exact same thing i just did with the h alpha but for the o3 so there's nothing new to show you there just getting all the o3 frames looking at the score and stacking them and then we'll have these two files to play with and we're going to combine them [Music] today's video is sponsored by canva now probably a lot of you don't know this but i used to be a graphic designer and i remember back in the day i looked at canada as something you used to if you didn't have a background in graphic design you want to create an infographic you use canva and you can make some kind of cool nifty designs but you kind of tell that it was like this boxed in template design well that has all changed canva does a lot more than little graphics and infographics now you can do videos and presentations and social media posts and all the stuff that you know you see these successful creators doing it looks like they have like a full team behind them of designers creating this stuff but you'd be surprised at what you can do in canva so it's something that i'm using now the canva pro account and i want you guys to be in on this too so if you click the link in the description you get an extended 45 day free trial of a canva pro account so thank you canada for sponsoring this video and have fun aren't you so glad i introduced canva to you i showed you camera like five years ago alright so the same process was applied to the o3 and the stacking from dss the multiple knights with the tabs there now let's take a look at this 03 file which it's named autosave001.tiff we're going to go into pixensight and open that up and put it in the same folder and i'm again going to use that auto stretch function just to preview what we've got in there here we go okay so you know a surprising amount of detail for o3 a lot of times the difference between the the o3 and the ha is is drastic uh the stars are a lot fatter in that which is you know something we're going to have to deal with there too so there's my o3 on the left and my h8 on the right now we're going to go through the process of aligning these images together using adobe photoshop now there are ways to do this in pixel sight but for now i prefer to do it in photoshop and maybe you will too so we have our preview stretched ha and 03 images here now the o3 on the left and the h a on the right now there's a very powerful tool called star net plus plus and i've talked about it before and if you're not using this tool you really should for astrophotography it's just so handy so what we're going to do is remove the stars from both of these images at this stage so we can turn off that auto stretch by hitting the the cross sign here i'm going to turn them both off and i'm actually going to do an actual stretch to these images using the screen transfer function if you've never done this process in pixensight it's one of the most simple actions to take it's you know widely used and it's found here in the all processes screen transfer function looks like this and then you'll also want your histogram transformation window open there we go so with my o3 we'll start with open i'm going to press again this nuclear icon the auto stretch and it's going to blast out the details there and actually do a great good job of not pulling the stars with it but to apply that i need to make sure i'm on the right file here auto save one you're going to drag the little triangle down here and then press the square to run it good old pixen site and again whoa white image what are we seeing here we're seeing the preview on top of the stretch so we need to turn the preview stretch off now this is the actual image we have here so we can save it in this state so i'm just going to save this file i'm going to call it 03 stretch 1. save it as a 32-bit file we'll be changing that to 16-bit after unfortunately but for now it's 13-bit in all its glory and we're going to do the exact same thing now to the aha exposure integration i should say now depending on your computer some of these actions might take a while to complete it's very processor intensive so again let's just grab the screen transfer functions there and then auto save is the file we want and i will press this icon here boom bring the triangle down square turn that off and now we've got this file ready to save save as h a stretch one so we've got our two stretched files now we're going to remove those stars from the image we'll put them back afterwards but we want to get them on as two separate layers very very powerful technique okay so we'll start with the ha and you have to install it in the right folder in your computer there's tutorials on how to do this um this is one of the things that my friend jeff walked me through was getting starnet integrated into pixensight but if you do some searching you'll find out exactly what you need to do here and it is now an option here in the the processes it's called starnet and you want to make sure that create star mask is checked and we can apply hitting a square button and if this is going to take some time it's going to carefully decide what the stars are in the image and do its best anyway and remove them into its own layer then we'll have the star layer and the starless layer plus it's finally finished and we are delivered with the starless version and then a star layer and look at that starless version it's just an incredible looking image that beautiful data and h alpha this is where when i said you know the asi 2600 mm pro the dynamic range and just the the resolution is just mind blowing how great these images look so uh that's the power of startup plus plus two to get that separation of the stars from the base nebula image so we're gonna do the exact same thing on the o3 now and yeah like i said it takes a while it's 20 minutes in between recording here so i'm going to start the o3 now starnet has finished its process on the o3 data so we now have the aha images the 003 stacked image with the stars separated on each now here's where we're going to go back into photoshop to combine the images and align them and associate them with the color channels to create a full color image there are ways to do this in pixel site but again like i said this is something i personally prefer to do in photoshop at this stage although maybe down the road it's something i'll do in pixensight itself because there are some great tools for that so i'll just save these images now so i can bring them into photoshop my ha stretch i'm just going to save that as aj stretch starless and then i'll save the star mask as aj stretch mask and i'll do the same thing for the o3 stack and bring it into photoshop okay we're in adobe photoshop now and i have those images we created in pixel site as layers in a single image here in photoshop so if you look at my layers palette you can see i've named them all so we can keep things organized we've got the o3 starless image on the bottom the stars themselves from that image on top of that then we've got the aj stylist image and the aha stars on top of that and if you notice those little chain link icons that's because those layers are linked and they will move together which is really important because we're trying to line things up the only reason these stars are here right now is because they're useful reference points to align them so we can put those color channels in the right place so if we look here at the bottom we can turn the star layer on and off on the o3 but there's a blend mode where you can actually see the stars through with the nebula through it so that blend mode is linear dodge add now we can see them both together i'll do the same thing with the h a starless image and the stars on top of there and now we have both linked layers on top of each other now i've lined them up already by slightly moving them around using the move tool but i just want to show you how i accomplish that so if i go to this h a starless layer which is on top of the o3 layer and bump the opacity down to zero but i have the the star layer still at a hundred percent you'll see when i use the move tool to move it around see those stars moving around they're moving around with that starless layer as well we can't see it because we've turned it down to zero percent but it is moving around with it and we know those are aligned so if we line up this star layer on top of the the other star layer from the o3 we'll know that our starless images are completely lined up now this might take a bit of time and you might need to zoom in but i'm just using the arrow keys on my keyboard and the move tool and you should get things to line up perfectly if there was a lot of rotation or your framing was off this will be a lot more difficult but hopefully if you shot it during the same session or if you use plate solving you should be right in the same area which makes it very easy so we can confirm that we've got things lined up properly by turning the starless layer all the way back up to 100 percent and then i'm going to turn both of these star layers off and we're just going to see those the starless data on top of each other so we've got the o3 on the bottom watch what happens when i turn the ha off you can see it's totally lined up but it's separating those gases of the o3 and the ha very interesting fun time to play with the image it's like okay so there's the areas of hydrogen or in this case right now the the oxygen and now the hydrogen it's very different so those are the layers we're going to use to assign two colors to greater full color image and this is where it gets really interesting this is a really exciting stage of the process because you finally get to see your color image so seeing as how we shot through only two narrow band filters o three and h a this is we didn't shoot s2 so we're not going to be able to create that hubble palette image which with dedicated channels to each but we can create an hoo image which is a popular color palette and it turns out really nice on emission nebula like the pelican nebula so the h alpha goes to the red and then the o3 goes to the green and blue channels what you're looking at here is that palette in action so if we go into the channels here you'll see that the red channel this is our h alpha all i did was copy and paste our h alpha image into the red channel of a new image then if we go to green that's our o3 and blue again are o3 now you can leave the green and blue as they are but i would probably suggest you know in this case to boost up that blue and and bump down the green just to achieve kind of a pleasing look so here's what we start out with which is already a super exciting image of course it's starless we don't have that star layer on right now which is super important that we're playing with this data without bringing the stars along with us at this stage so i have a pretty intense set of layers in here my first layer here is just that rgb layer it's got those channels in there the the hoo and then i pulled out each channel as its own layer to play with that individually so here's the red and what i did was go into adobe camera raw which is a very powerful set of tools in photoshop so you just find that into in filter camera raw filter and then here's where you'll be able to do things like anything from sharpening to noise reduction to curves to clarity and dehaze are some of my favorites uh if you look at what's happening with the the clarity slider very powerful stuff there for achieving a high dynamic range and all of this is possible because the data is so great captured with this asi 2600 mm pro and this is probably the biggest reason or it is the biggest reason why this is probably my best photo to date because the data is the highest quality i've ever taken thanks largely to the the camera sensor in the asi 2600 and that three nanometer chroma filter i'm using so these are the kinds of adjustments you can make in adobe camera raw i'll just cancel this this is what i ended up with after making camera raw filter effects to my red channel here's the green after that my slight adjustments to the green channel the blue channel my slight adjustments there and you can see i pulled that blue up a little bit more to get the look i want when i put them all back together in the channels rgb this is the image i've ended up with so if we look at a before and after making those camera raw adjustments to each layer individually each channel individually quite a dramatic difference in a very different looking image overall then with this color image you can directly apply more camera raw adobe camera raw edits and this is what i did there so this i call this the the color enhanced version i applied some of those things clarity um played with the curves a little bit in adobe camera raw on the on the full color image as a whole then i was i thought the image was getting a little bit red and there was a little too much blue so i adjusted the levels here kind of adjusted that black point if you're you know if you're you're new to image processing and things like blackpoint are still uh foreign to you i urge you to check out my image processing guide where i go really beginner level stuff um close to where i'm at now so that's that version and this image excites me as it is here but then the the cherry on top is to pull that red h alpha layer this one and apply that as a luminance layer on top and look at the subtle dramatic difference that makes so all you do for a luminance layer if it was a normal layer you could see this black and white h alpha you set the blend mode to luminosity and just like that at 100 i really do like the way that looks but i actually bumped it down to about 60 percent and it just made that pop it just oh i love the way this looks and if you want to add those stars back in i mean people do like starless images i prefer to actually have stars in the image most times so to finalize things there's that star layer which of course lines up perfectly because we kept it in the same orientation we can turn it on i chose the the h alpha stars they're not the natural colors they're just white stars but that layer is on top of the color image with the blend mode set to linear dodge add so many different things you can do in between where i got to here including making those stars smaller if you want to before putting them on so now we're going to hop into pixel sight i'll show you how to do that and some final tweaks to this image to really make it oh so you'll probably want to save the image in this format with all those layers so you can go back and make adjustments non-destructive workflow but for the sake of this tutorial i'm just going to flatten the image and this is where we're going to crop it too you can see there is some overlap here where my frames didn't line up between filters and of course that white bar at the top so i'll just use the crop tool and crop the image in just to frame it up nicely if you did a good job in the acquisition stage you won't need to crop up very much if you framed your image between filters up nicely okay so we'll crop it right here press enter we've got close to what our final image is going to look like and i'll just save it in the folder here color as a tiff and now i'm going to go into pixen site open our color image here's some really cool things you can do so there's a few tools that my good buddy jeff taught me that i like to use some finishing touch stuff in pixel sight that i like to use one of them is already open here it's called morphological transformation now you may want to use this tool just on your star layer itself to shrink those stars it erodes the stars and gets them smaller which is a pleasing effect most of the time you can use it on the image with your your nebula in there too and the stars i'm just going to show you kind of what this this filter does in action uh but i i do recommend running it on the star layer independently from your main image but i just wanted to show you this here so i've got it set to the absolute default settings and you'll find that uh that's the way i use pixinside a lot right now it's just at the default settings the amount starts by default at 1.0 i find it to be a bit aggressive and it really just chunks away those stars and just almost removes them completely i i run it at 50 percent so at 0.5 and then when i run it here pressing the square you'll see the difference 77 okay so um you know just right off the off the bat out of the gate looking at it here it does look like an improvement a more dramatic image but of course we can do the before and after to see what it did so it did if we zoom in it did erode those stars which is always nice but it also you know affected our nebulosity here in some of the dark dust and it softened things up and things kind of grew so in this case i'm not going to run it but it's a it's a useful tool you should check out the morphological transformation especially for eroding your star layer independently so that's one of them and then another one that i wanted to show you that's really cool is the hdr multi-scale transform this one is very interesting it's it's a very dramatic effect and very experimental in my experiences so i'm going to leave it again on the default setting you can you know play around with your hearts to light i'll run the filter here and this is going to add some crazy details to it uh and really find some dynamic range in the image that you may not have thought to to pull out yourself manually in photoshop so it it this always dulls the color of the image i find but if we go in here so i've ran the filter here so this is a probably a good spot to check out what it's done because there's some varying contrast of brightness here if we look at the before and after it's pulled some of this these subtle areas of dust in kind of those mid-range areas so what i always do with this this tool is just get back out i save a version just called details so i've got my hdr multiscale transform detail layer and then i open it in photoshop this is a ninja trick i can't believe i'm sharing this i copy this layer onto our original and then you might want to because it did dull those colors a little bit you might want to just increase the the vibrance and the saturation just so it's not as dramatic so we've got this pretty wild detail layer here make adjustments to it beforehand if you want that was a little too aggressive let's just go back here we'll just use use it as is i'll put my original layer on top and now in those areas where you think you can recover some of that dynamic range and those really important details you can use the eraser brush or spend time creating a mask if you want but i like to just reveal some of those details from behind my main image and it's a very subtle effect so i'm using it let's get the right layer here turn the opacity of the eraser down to 30 percent and we're just subtly clicking away and revealing details in some of these really key areas again you'll probably want to adjust that detail layer to get that vibrance and those colors right before you do it but if you can really get in there and start revealing some of those areas probably best to create a really nice mask too where you just have the bright areas and removing those detailed areas but creating that detail layer and revealing it in the areas where it needs it is a very powerful technique and something i've been i've been experimenting with and really find it powerful so we'll go back to pixen site to our regular color image and this is this is the term that everyone likes to throw around that's a pixel sight user something that's scared that scared me to use it because uh you know i just didn't understand what it meant i still don't know exactly what it means it's the deconvolution which i wish they would just call it what it is sharpening it sharpens your image now there's a lot of things you can do to control uh the way it handles the stars in your image and you know the de-ringing and everything and uh you should probably check out sean nielsen visibledarkastro his youtube channel he's got a lot of in-depth stuff on pixel site but i found that using deconvolution the default settings can have a really nice effect so definitely try it out here's what it does it's going to do 10 iterations and this really does sharpen better than any other sharpening tool i've ever done in photoshop and because i really haven't refined it before running it i like to again use it as maybe a 15 20 layer on my main image so let's look at the before and after oh so subtle but man you can really see the difference in the sharpness of these areas of dark dust it's a really magical tool so you can experiment with that but even i found i was so surprised that in its default setting it works really really well this is pretty close to the final image that i shared in my last video so hopefully those uh tips sunk in i didn't move along too fast i didn't mumble too much and that you got something out of this video and the way i now use photoshop and pixensight together to create really dramatic looking images so this is the hoo palette bi-color image using narrowband data from the city if you like this video please give it a thumbs up if you want to check out my image processing guide for more in-depth and more beginner level stuff start to finish you can always check out that anyways hope you enjoyed this and until next time clear skies [Music] you

Channel: AstroBackyard

Views: 43,334

Keywords: astrophotography image processing tutorial, astrophotography, image processing, tutorial, deep space, deep sky, astrobackyard, adobe photoshop, photoshop, pixinsight, deepskystacker, stacking tutorial, how to, astrophotography tutorial, beginner, trevor jones, how to process astrophotography images, how to edit astrophotography images, how to edit photos, how to use pixinsight

Id: ph-cpjqlv0Q

Length: 32min 52sec (1972 seconds)

Published: Fri May 28 2021