/astrostack — Astro Image Stacker
Load a burst of night-sky frames and stack them to cut noise. Stars are detected and every frame is aligned to a reference, then combined with a sigma-clipped or plain average, an optional dark-frame subtraction and an asinh stretch. Everything runs in your browser — nothing is uploaded. Planning a shoot? See /astroplan.
How to shoot for stacking
Put the camera or phone on a tripod, focus manually on a bright star, then take 10–50 identical frames a couple of seconds apart (use a 2s timer to avoid shake). Keep exposure short enough that stars stay points. More frames means less noise. Optionally shoot a few "dark" frames with the lens capped at the same settings to subtract sensor noise.
Drop light frames here, or
2–200 frames of the night sky