StackFast

Image stacking for astrophotography

Stack a night of exposures in seconds.

StackFast lines up your light frames, throws out satellite trails and hot pixels, and hands you one clean image. About 20 times faster than Siril.

Windows app coming soon Watch it race Siril
The Lagoon and Trifid nebulae, stacked from 20 frames
Lagoon and Trifid nebulae 20 frames of 180 s, 26 megapixels each. Stacked in 1.6 s.
01

From a folder of photos to a finished image

StackFast Send feedbackAccount: you@example.com

1. Light frames

Choose another folder...

M8_M20_lights

20 frames · 6248 x 4176 · 1.0 GB

2. Settings

Outlier rejection

Lower removes more satellites, planes and hot pixels. Default: 5.

3. Stack

Stack 20 frames

Done in 1.6 s

4. Save

Save image as TIFF, PNG or FITS...
Display:Auto stretchBrightLinearFit to window
The StackFast window. Choose a folder, press Stack, check the result, save.
  1. 1

    Choose your folder

    Point StackFast at the folder with your light frames. It counts them and checks that they match.

    20 frames found
  2. 2

    Press Stack

    Frames are lined up, trails and hot pixels are thrown out, and the rest is combined. There are no settings to learn.

    Frame 9 of 20
  3. 3

    Look at the result

    Your image appears straight away. Zoom in, switch the brightness view, and check the stars before you save.

    Auto stretch
  4. 4

    Save and keep editing

    Save as 16-bit TIFF, PNG or FITS and carry on in the editing software you already use.

    TIFF, PNG, FITS
02

20× faster than Siril

Same 20 photos, same computer. Both start from a single noisy frame and clear up as more frames are added. Watch which one finishes first.

StackFast
The finished stack from StackFast
1.6 sFrame 20 of 20
Siril
The finished stack from Siril
33 sFrame 20 of 20

Each picture is a 2× zoom into the Lagoon nebula, so you can see the grain. Real timings for 20 frames of 26 megapixels, with Siril on its default stacking settings. Sample data from the Siril tutorials. Your results will vary with your data and computer.

03

What you get

Trails and hot pixels removed
Satellite streaks, aircraft lights, cosmic rays and hot pixels are rejected automatically.
Aligned for you
Drift between frames, and even a meridian flip, are corrected. No reference frame to pick and nothing to tune.
Preview and export
See the stretched result right away, then save 16-bit TIFF, PNG or 32-bit FITS.
Your photos stay on your PC
Everything is stacked on your own computer and your images are never uploaded. Sign in once; it keeps working offline for up to a week.

What you need

  • Windows 10 or 11. A graphics card is not needed.
  • Light frames as 16-bit FITS files, all from one session. Colour or mono camera.
  • Darks, flats and bias calibration are not built in yet.
04

Coming soon

The StackFast Windows app is almost ready. Create your free account now and you will be ready to sign in on day one.

Free during the beta. Questions or feedback: proxylabsmail@gmail.com