StarSift

A desktop app that finds the frames that would spoil a stack - trailed stars, clouds, haze, soft focus - and tells you why

StarSift looks at the pixels of every light frame, compares each one with the rest of its night, and tells you which frames will hurt your stack and why. It is a separate app from DeepSkyLog, for Windows, macOS and Linux, and is currently in beta.

StarSift after scanning a night of NGC 7380: 68 frames kept and 24 rejected, each with the reason, the star profile and the stars across the field

What it does

  • Measures every frame from its pixels - star size (FWHM, HFR), elongation, star count, sky brightness and halos - so it works with frames from any capture software, ASIAIR included.
  • Judges each frame against its own night. Trailed stars, passing cloud or haze, a soft patch after a focus drift: each rejected frame says what is wrong with it, in plain words.
  • Night report. One picture of the whole night - star size, brightness and altitude through the night, the meridian flip, what was kept and what was lost to clouds or seeing.
  • Moves, never deletes. Rejected frames go into a folder beside the others, so your stacking software skips them. Nothing is deleted, and anything can be moved back.
  • Everything stays on your computer. Frames are read and measured locally.

The night report: star size through the night against altitude and brightness, with each rejected frame marked by its reason

StarSift and DeepSkyLog

StarSift signs in with your DeepSkyLog account. To send your sessions to DeepSkyLog, use the free DeepSkyLog Uploader - you do not need StarSift for that.

Availability

StarSift is in beta and will be sold separately from DeepSkyLog. I’ll announce the price and the download here.