Astrophotography Calculator

Work out the best settings for photographing an array of astrophotography subjects

Astro calculator

Choose what you want to photograph in the night sky, tell us about your camera and film, and get the lens, exposure and timing to aim for.

mm
ISO

Exposure suggestions are starting points for a dark, clear night. Bracket your exposures, since sky brightness, altitude and haze all change what you need. Film loses sensitivity on long exposures, and this tool corrects for that using the reciprocity data for your film stock.