this week I'm going to show you how to stack your astrophotography images
as there's not much light about at night you really have to bump up your iso so
this means an increased noise pattern in your images so in stacking the shots and
taking things called dart frames you can really reduce this noise I am going to
be using Lightroom and Photoshop in this tutorial so if you don't have these
click on the link in the description and this will take you to a free trial also
there is a link in the description to the raw files that I used in this
tutorial if you don't have access to dark skies this will still give you the
opportunity to stack these images together I've also included two edited
images one from stacking and one from a single image so you can see the
difference for yourselves in this video I'm only gonna use starry landscape
stacker but if you have a PC you can download the free software sequitur I've
left a link in the description to both of these programs you can stack them in
Photoshop and you can move the images around to get them lined up but it is a
long tedious drawn-out process if you're not sure how to shoot the stars but want
to learn more click on the I in the corner or the link in the description to
my Astro photography tutorial I do use the a 7-3 in it but no matter what
camera you use you can follow along and just copy the settings into your own
camera system basically you need to take a sequence of photographs and then stack
them in the computer afterwards your camera needs to be perfectly still
between images so it can actually blend them together in the sequence
I shot 20 images of the night sky and then I did 10 dark frames duck frames
are basically a way to get an image of just the noise your camera produces for
the night and those conditions all you do is basically keep the camera on the
same settings put the lens cap on and take another series of frames you can
either shoot these separately by pressing the shutter button after each
shot is completed or use the new interval function if you have the a7 3
or the a7 r3 to do this go to tab 1 4 or 14 and select intervals shoot function
turn intervals shoot on set the number of shots to 20 as you're shooting at
night you should be in manual mode which blanks out shoot interval priority
if not this should be off so the exposure time overrides the interval
time this will then give you minimal gaps between shots once you get a good
composition your focus is correct and your settings are good press the shutter
button and wait for the camera to take this sequence once done change the
number of shots to 10 put the lens cap on and take these 10 dark frames with
exactly the same settings as the 20 light frames the only difference is
you've got the lens cap on so you're not going to get any data of the sky this is
just to record the noise pattern of your camera on that night for the given
conditions then it's time to process your images once you've imported your
photographs into Lightroom you need to make a few changes before exporting TIFF
files for starry landscapes tacker also it's good to create a mask for the
foreground so I'll show you how to do that as well if you do have any abnormal
frames in the sequence like if there's a road going through the shots and there
are light streaks and the frames are different this is what can mess up the
stacking process so basically make sure there's no light streaks from cars in
the shots airplane trails are okay as well as small shooting stars so once in
Lightroom I'll select the first image and then set my white balance I under
expose my shots as I have an ISO invariant camera but if you shoot with a
canon or one with a variant sensor you'll have to get a good image in
camera I'll then push my contrast all the way down I'll bring the blacks up a
little bit going down to details of remove all the sharpening and noise
reduction and then in lens Corrections of remove chromatic aberrations then
switch it to manual and remove any vignette ian's is producing in this
sequence I used the twelve millimeter Laur and there's quite a bit of
vignetting I always find that looking at the thumbnail in the top left-hand
corner helps me see the overall vignetting once I've made all these
changes is time to sync all of the shots so select them all including the dark
frames and sync all when exporting the images select the file type as tiff srgb
and a 16-bit I don't put any compression on it I don't resize an Allred
ten all the metadata Elend save them all to one folder including the dark frames
next it's time to create a mask you can manually do this in starry landscape
stacker but I prefer to do it in Photoshop for a more accurate mask to do
this right-click on one of the images and then open it up in Photoshop
once opened click on select and then select and mask what's in this selected
mask start painting out the sky if it paints out everything you might have to
paint back in the land or foreground you can do this by holding down option and
painting it back out if you have any trees or details along the horizon click
the refine tool and paint these out if you're having trouble doing it this way
you may have to invert your mask but there are plenty of tutorials on this on
YouTube I've linked one to the eye in the corner and I put a link in the
description then click view and select overlay this will show you in red what
will be masked out I then use global refinements to clean up the mask I'll
normally add a bit of contrast and then a little bit of feathering after that
click OK then select the mask select all select copy select a new set greyscale
8-bit and create a new image then paste the mask in hide the bottom layer and
then save as a tiff file without layers name it mask and in the same folder
you've exported your images to next open starry landscape stacker and then import
all the images it should automatically add the mask and know which ones are the
dark frames and which ones are the light frames the light frames are basically
the images that you've taken of the night sky if you have a high megapixel
camera it'll take a while as these TIFF files are really big
then enter your focal length you can ignore fine sky as you've already
created a mask if you skipped creating your own mask this would be the time to
do it and you use these tools as a normal masking tool system if you didn't
create a mask in Photoshop this is what you'll see when you import your images
it should pick up most of the stars with these red dots if
there are any red dots on the foreground you need to get rid of these just make
sure you've selected arrays red dots and then rub them out once you've done this
click find sky it will then attempt to build a mask so
you can see now why creating a mask in Photoshop is so much better now all you
need to do is paint the rest of the sky in just make sure the sky is selected
and paint up to the horizon if you do paint over the horizon click on ground
and then rub that bit back out with this example it's pretty straightforward as
the horizon is quite flat but say if you've got trees protruding up from the
horizon it'll be a little bit more tricky I'm going to roughly paint this
in but you can be as precise as you want as I said before this is why I prefer
creating my masks in Photoshop and then importing them into starry landscape
stacker once it looks okay click align with this will give you a preview if you
don't like how the Milky Way looks in the sky you can change the current image
but I like it where it is so I'll click a line and composite it will then
process the final image at this point you can choose to save just the image or
the image and a mask of the sky if you don't need a separate mask of the sky
and check this box then click Save name the stacked image and then the mask if
you have selected that option once saved bring the image into Lightroom and edit
as normal if you want to learn more about editing in Lightroom click on the
I in the corner to another of my tutorials so I've edited two shots one
stacked and one single image you can see that the sky is a lot clearer in the
stacked one and the foreground is so much less noisy I was actually really
surprised at how much cleaner the foreground was I thought it would blend
and get rid of noise in the stars but I wasn't sure how well it would do on the
foreground so this is really good you can see that the single image has a lot
of noise including long exposure noise whereas this stacked image doesn't have
this I probably should have shortened my exposure time as the stars are starting
to streak but when zoomed out they look fine and that's
about it if you want to reduce noise in your astrophotography shots starry
landscape stacker or stacking your images in a program like sequitur is a
really viable option after doing this test I think I'm gonna start stacking my
shots more and more I've shot around about 10 years of astrophotography shots
and I've always taken single images I've almost seen it as a bit of a challenge
to try and get the shot in one image but after doing this test I think I'm gonna
start stacking more as always if you like what you see give me a thumbs up if
you didn't give me a thumbs down and for weekly tutorials hints and tips in
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in the next one