You may have heard about how stacking drastically improves your night images, but just how many photos should you stack with programs like Starry Landscape Stacker and Sequator?

I often get asked this question when it comes to my stacked night photos, so I decided to run some tests. While on a trip at Block Island, just off the coast of Rhode Island, I went to North Lighthouse and patiently waited for the Milky Way to rise. During that waiting period I took thirty photos at a typical setting I liked to use when stacking my night sky. My settings and gear were as followed:

Nikon 800 with a Nikon 14-24mm lens at 24mm set to F3.2 ISO 6400 and a Shutter of 10 seconds to prevent motion blur with the stars. I stacked the photos in increments of 5. So I made a stack of 5, 10, 15, 20, 25 and 30 photos. I pixel peeped them at 400 percent to see the benefits of stacking more photos with Starry Landscape Stacker which I presume would be similar results in Sequator as well. I blew up side by side comparisons of this photo with the various stack quantities stated earlier.

Feel free to click the images to get a larger view of them to help see the differences. From these tests I noticed that there is a vast improvement when stacking more images which is to be expected, however it does seem to level off when you start stacking 20 images or more. The difference between stacking 20 vs 30 images is negligible even when zoomed in at extreme magnifications. Some could even argue that 10 to 15 stacked images would probably be sufficient for most night photographers. Ultimately it boils down to personal preference and time. I can’t tell you the perfect number of photos to stack for the best results, but I can recommend a certain length of time. For example, if you like the results of 20 photos stacked then look at the amount of time involved for that exposure.

20 photos x 10 second exposures = 200 seconds (3 minutes 20 seconds)

So if 3 minutes and 20 seconds gives me good results with my stacks then I will adjust the number photos based on the exposure time to equal 3 minutes 20 seconds. So for example, if I use a 50 mm lens and take a 5 second exposure, then in theory I should be able to stack 40 photos to achieve similar results as 20 stacked photos at 10 second exposures.

I have not had a chance to test out that theory just yet, however these test results should still help you get pointed in the right direction when trying to figure out how many photos you should take for you stack! If you are interested in watching my video about this topic please click below.