Stacks of Stars – For Less Noise
by Rodney Campbell on May.16, 2019, under Life, Photography
Stacks of Stars
Something Gerry suggested whilst we were shooting some static milky way shots this evening
Stacking a number of short exposure star images together for less noise and better stars
It is something I’d heard of before, and a technique I knew was used in astro photography. However I’d never used it myself
So I dutifully took a sequence of short (15 second) static milky way frames… to later look at in post processing and ignore and move on 🙂
However in post… I was going to blend this (219 sec) light painted foreground shot with a nice static milky way shot. I’d need to do this because the stars were not pinpoints but long trails in a 219 second exposure
Since I was already going to photoshop to do the blend I figured I might as well try stacking my star stacks
The process is basically simple:
- Open your short star images as layers in photoshop
- Mask out the foreground (on all layers) (so they don’t affect the next step)
- Align all the layers so the stars are all aligned (I used auto align layers for this but you may have to manually align)
- Remove the masking on the foreground
- Stack all of the star layers as a Smart Object
- Set the Smart Object -> Stack Mode to Median
The end result is an image with sharp stars but with far less noise than a single image