I’m headed to Fairbanks in a couple of days to photograph the northern lights. Now if the weather will cooperate, like it did last year, we should have some fantastic photography. Photographing the night sky involves capturing stars in your image, and that brings up the question of coma.
Coma is an aberration of the lens or design which renders point sources of light as saucers. Take any of your star images and zoom into close at 100 percent and more. If your stars are circular, you have minimal coma and a terrific lens for astral photography. If you stars seems stretched out, more oval in shape, then you have some degree of coma with that lens.
There are some fantastic lenses for night photography that have minimal coma…the Nikon 14-24mm F2.8, the Rokinon 24mm 1.4. Related to this coma discussion is this review of the new Nikon 14-30mm Z…interesting comments on how this lens renders points of light.
In practical terms, will you really see coma in your images? For most of us, probably not. If you make small prints or have images published in magazines, you should be fine. If you make very large prints, you might see it. Find out more about your favorite night photography lens. Take some images, blow them up to 200 percent or more, and take a look for coma.