BlinkFits
4 minute read
BlinkFits 1.0Blink comparator for FITS
Blink your subs.
Spot what moved.
BlinkFits flips back and forth between frames, with zoom, pan and stretch held perfectly still. Asteroids, novae, variable stars, satellite trails and subs worth throwing away jump out at you.
Need an older version? All releases are on GitHub.
Extract the zip, then run blinkfits.exe. No installer needed.
(Get-FileHash .\blinkfits.exe).Hash -eq (Get-Content .\blinkfits.exe.sha256).Split()[0]True means the exe matches the SHA-256 in blinkfits.exe.sha256, which comes in the zip.
Windows warns when you start it? Here is what to do.
- Free
- Windows 10 / 11, 64 bit
- No installer
- Offline, no telemetry
Every star stays put. The one that jumps is your minor planet.
Made for a night’s worth of subs
Load a folder, press the arrow keys, and see what changed. Everything else stays out of the way.
The view never moves
Zoom, pan and stretch belong to the viewer, not the frame. Switch images and only the sky changes, which is the whole point of blinking.
Six stretches
Auto (STF) by default, plus levels, asinh, logarithmic, histogram equalisation and unstretched. Sliders react instantly, even on large frames.
Auto blink
From 0.1 s to 60 s per frame, wrapping at both ends. Space or Pause stops and resumes at the same speed, Reverse runs it backwards.
Mark the keepers (or the rejects)
One key renames the file on disk with your suffix: frame.fits becomes frame_tag.fits. It still shows next session, and in Explorer.
One shot colour
Debayer raw OSC frames from BAYERPAT in the header, or pick RGGB, BGGR, GRBG or GBRG. Each channel is stretched on its own for a neutral sky.
FITS header
Show the header cards in place of the image. Keep blinking and the header follows, frame by frame: exposure, gain, temperature, time.
Several folders
Add files and folders from different sessions to one list, drop any of them again, or pass paths on the command line.
Careful with memory
16 bit samples, a cache that fits your RAM, and a clear message instead of swapping your machine to a halt.
15 languages
English, Deutsch, Français, Italiano, Español, Português (BR / PT), Nederlands, Dansk, Svenska, Polski, Русский, Українська, 日本語 and 中文.
Hands on the keyboard
Blinking is fastest without the mouse.
| Key | Action |
|---|---|
| ← → or A D | Previous / next image; during auto blink, turn it round |
| Space | Start / stop auto blink |
| Home End | First / last image |
| M | Mark or unmark the current image |
| S | Next stretch method |
| 1 … 6 | Zoom 5, 10, 25, 50, 75, 100 % |
| F or 0 | Fit to window |
| N | Night vision: the interface in dim red, the image unchanged |
| F1 | Help |
| Esc | Close the FITS header, Help or About |
Files it reads
Straight from your capture software, no conversion.
- Uncompressed FITS with BITPIX 8, 16, 32, 64, −32 or −64, including BZERO / BSCALE and BLANK.
- Mono, raw Bayer and three plane colour images. Raw frames stay grey unless Debayer is on.
- Up to 200 MB per file. Larger ones are refused with a message.
- Not supported: tile compressed FITS (
ZIMAGE, e.g..fz).
What you need
- Windows 10 or 11, 64 bit. Nothing else: one exe, no installer, no runtime, no DLLs.
- Settings live in
%APPDATA%\blinkfits. Delete the exe and the folder and it is gone.
Windows warns when you start BlinkFits?
BlinkFits is a hobby project and the exe is not code signed. Windows treats new, unsigned programs with caution until enough people have run them.
Check the file. The zip contains blinkfits.exe.sha256 with the SHA-256 of the exe. After extracting, run the PowerShell check above, or run certutil -hashfile blinkfits.exe SHA256 in a command prompt and compare the result with that file. If they match, the exe arrived intact.
Windows SmartScreen (“Windows protected your PC”): click More info, then Run anyway.
Terms of use
BlinkFits may be downloaded and used free of charge by anyone, for any purpose. Redistributing, selling or modifying it, or passing it off as your own work, is not permitted without the author's written permission. It is provided as is, without any warranty.
Contact
Questions, bug reports, a FITS file that will not open? Write to raphi@crashdump.ch. Please share a link to this page rather than the download, so people always get the current version and its checksum.
© 2026 Raphael Debinski. All rights reserved.
Built with Go, Gio and go-text/typesetting; their open source licenses are shown in the program under About and apply to those components only.