OriginStack

What's new

The highlights of each release, in plain language. The full changelog has every change and the measurements behind them. To update, download the latest release; the app says in its header when a new one is out.

2.24 9 November 2026

2.24.0 9 Nov

  • Add your earlier stacks in one click. Choose a folder and, if you have already stacked the same target, a checkbox offers to add those earlier stacks to this one.
  • An optional GPU for the final combine. --gpu-coadd runs the last combining step on the graphics card (any maker). On the card it was built on it is nearly twice as fast; on a laptop it is about as fast as the processor, and it needs the laptop’s high-performance power plan. It checks itself and goes back to the processor when the card is slower, and it is off unless you ask for it.
  • Star catalogues load while you wait for the stack. The star lookups the position step needs, and the first one the colour step needs, now happen in the background while the frames are processed, so the first run on a new field pauses less afterwards. A slow catalogue server can never hold a run up for more than a few seconds.
  • A clearer name for the sharpening strength. The setting is now called “Learned sharpening strength”.
  • Fixes and clearer warnings. A red and green strip along the bottom edge of some stacks is gone, and merging stacks with very different sky brightness, or a colour fit that hits its limit, now says so in the log.

2.23 6 November 2026

2.23.0 6 Nov

  • A new desktop window. The app is rebuilt on Qt: a smoother picture viewer (zoom about the pointer, pan, a wipe line you can drag, a pixel inspector, true 1:1 viewing), light and dark themes that follow your system, and your layout and recent folders remembered between runs.
  • Edit the stretch after a run. A histogram with draggable black, symmetry and white points, a tone curve, undo and redo, and saved stretches. Phase 4 steps can be switched on and off and the picture updates, with a before-and-after of any single step.
  • Review your frames before stacking. A graph of every frame’s quality, star width and signal to noise shows a bad stretch of the night at once. Pick frames to leave out; the run waits five seconds for you, then carries on by itself. --exclude-frames does the same from the command line.
  • Progress on the taskbar. On Windows the taskbar button shows the run’s progress, turns yellow while it waits for you, red if it failed, and flashes when it finishes.
  • A fix for sessions with mixed dark frames. A session whose dark frames had different exposures could stack with a huge sky offset, a red cast and coloured blotches. Darks are now chosen and checked more carefully, and a dark that would damage the image is dropped with a warning.
  • A smaller download. The Windows installer is about 65 MB.

2.22 3 November 2026

2.22.2 5 Nov

  • No more blue discs on bright stars. In 2.22.1 the colour-keeping preview drew very bright stars and clipped nebula cores (Orion’s Trapezium) as flat blue dots. Bright cores now fade to white; stars that are not saturated keep their colour, so Pinwheel’s red stars stay red.

2.22.1 4 Nov

  • Stars keep their colour in the preview. The preview stretch now keeps each pixel’s red, green and blue ratios by default, so red giants stay orange or red and blue stars stay blue, instead of the brightest cores turning white. The old look is still there as --stretch-color channel.

2.22.0 3 Nov

  • The learned deconvolution and denoising step is about three times faster. On the Whirlpool stack that step went from 19 to 10 seconds and the whole post-processing from 25 to 16 seconds. The result is the same to the eye; individual pixels can differ in the last digits.
  • A first look while the stack is still being built. Right after the frames are aligned, the app shows a quick preview made from the eight sharpest frames, so you are not looking at an empty window for the longest step.
  • Update from inside the app. On the installed Windows version, “Update available” downloads the new installer, checks it against the release, closes the app and runs it. The other versions still open the download page.
  • Drop a folder on the window to choose your light frames (Windows), and My settings saves a set of options under a name so you can load it for the next session.
  • A tidier window. Sharp text on scaled displays, a histogram under the preview, a one-line summary before you start, an “Only changed” filter for the options, and a recent-frames table you can sort.
  • Free sample sessions. Twelve raw Origin sessions, one per kind of target, are on Zenodo for trying the program; the website links them.

2.21 2 November 2026

2.21.0 2 Nov

  • The flat that ships with the Origin keeps its detail. It was smoothed as if it were one noisy frame, which erased the sensor’s real pixel pattern. On a 158-frame stack the sky came out 1.8 to 3.7% smoother at the 16-pixel scale.
  • Cold sessions get a better dark. Amplifier glow depends on temperature, so a dark taken warm over-subtracts it from a session shot cold. A few lights are used to fit the glow scale; it only applies when the fit is clear (3 of 11 local sessions). On a session 11 °C colder than its dark the stack had 10 to 13% less large-scale blotchiness.
  • Cleaner edges on extended stacks. With --full-field the rims are covered by fewer frames and are noisier; both denoisers now even that out first. The wavelet denoiser also estimates each band’s noise separately, so it no longer leaves most of the noise in correlated data. The preview JPEG is dithered, so smooth denoised areas do not band.
  • New and optional: halo subtraction anchored on Gaia, and a tilt equaliser. The first models bright stars’ wide wings from your own stack and the catalogue and takes them out (Pleiades wings at 40 pixels fell from 16–23 to 4–8 sigma, nebulae untouched). The second runs the learned sharpening once more where the stars are wider; every Origin stack measured has stars 12 to 55% wider along one sensor axis. Both are off by default; see advanced features for the limits.
  • Tools that measure rather than guess. A frame’s effective exposure in the report, the finest detail a stack really holds (from two half-stacks), a test that adds faint fake nebulosity and reports how much of it survives, and star-width maps. The full list and the numbers are in the changelog.

2.20 1 November 2026

2.20.0 1 Nov

  • The learned sharpening works on other cameras. It measures the stars in your stack and rescales to the size it was trained on, so a different pixel size no longer matters. Checked on Seestar S50 and Las Cumbres Observatory stacks. Monochrome and tile-compressed FITS now load, and the automatic settings choose it when they can measure the stars.
  • Compare any finishing step before and after. A Before / after button in the post-processing panel opens a slider window with zoom and pan.
  • See why each frame was kept or rejected. --frame-report writes a table with a plain reason for every frame.
  • Mixed folders and odd calibration frames. A larger dark or flat is cropped to fit when that is safe, and lights shot with different binning, size or gain are stacked separately instead of mixed.
  • Star removal (experimental) takes out the cores of the brightest stars and works on monochrome stacks. The app can copy a diagnostics report, remembers your folders, and says when your camera is not an Origin. --nn-deconv-blend sets the sharpening strength.

2.19 30 October 2026

2.19.0 30 Oct

  • Switch finishing steps off and on after a run. A Post-processing steps panel under the preview has a box per step the run used. Ticking or clearing one redoes only that step and the ones after it, so a late step takes a few seconds instead of a whole Phase 4. A Show without stars box previews the image without its stars.
  • Pick a frame to see it. The strip of thumbnails is gone; click a row of the recent-frames table, or step through it with the arrow keys, to see that frame in the preview. It stays up while the run continues; choose a stage from the drop-down to follow the run again. Every frame gets a thumbnail now, and Phase 1 got quicker for it: 44 s instead of 64 s on a 158-frame session.
  • Re-running from a saved config matches the original run. --auto no longer asks for per-frame gradient removal, which only ever ran when the saved config switched it on and changed which frames passed the quality gates.
  • A mosaic tile much fainter than its neighbours is named in a warning, and the Gaussian blur and bilateral filter run faster.

2.18 28 October 2026

2.18.0 28 Oct

  • Seestar S50 and S50 Pro. Choose the _sub folder of frames and press Start. The first frame is plate-solved from its own header, so the colours are set from Gaia stars as on an Origin session. See Other cameras.
  • Galaxies keep their faint outer light when a session has no flats. A flat used to be made from the lights themselves, and it took most of the galaxy's halo with it: about 95% of M31's disk on an S50 Pro. That flat is now made only when you ask for it.
  • Andromeda, Orion and the Horsehead look right at the default settings. No dark discs around the stars on M31, a smooth Orion core instead of a white cut-out, and the Horsehead stands out against its glowing nebula again.
  • Copy a problem report. Report a problem can now copy the report (version, system, error and the end of the log, with your home folder hidden) for an email or a forum post, without a GitHub account.
  • Frames copied from a Mac zip no longer pick up its hidden ._ files, and a run no longer waits 20 seconds when a catalogue server cannot be reached.

2.17 27 October 2026

2.17.0 27 Oct

  • Comets are stacked on the comet. When the target is a comet (C/2025 R2, 12P/..., 3I/ATLAS), you now also get a stack aligned on the comet and a blended image with a sharp comet on sharp stars. The comet is located with its JPL Horizons ephemeris, so a passing satellite is no longer mistaken for it. --no-comet-mode turns it off.
  • More of the frame is kept. The edges that drift, dithering and field rotation leave partly covered are now stacked from the frames that cover them instead of cropped away.
  • Cleaner multi-night images. Combined nights no longer show coloured rims and wedges where only one or two nights reach; the image is cut to the area most of them cover.
  • Nebula-filter sessions keep their colour. Through an OIII or dual-band filter the nebula now comes out brighter, in its own colour.
  • Sharper drizzled stacks, --config KEY=VALUE settings that work as documented, and the streamed stack (--stream) now uses the learned sharpening too.

2.16 26 October 2026

2.16.0 26 Oct

  • Sharper stars in every image from an Origin. The learned sharpening was retrained against sharp, deep survey images of the same sky and is now used automatically for every target, not only galaxies: stars about 15% narrower on galaxies and 10-35% narrower on nebulae and clusters, with the same or more faint detail. The sharpening step takes about twice as long as before.
  • Cleaner learned star removal (experimental, --remove-stars-method nn): no more coloured discs and rims where bright stars were.
  • Three more processing steps use the fast native module.

2.15 24 October 2026

2.15.0 24 Oct

  • Sharper multi-night images. When several nights are combined, each night now counts for the fine detail by how sharp its stars are, so one night of poor seeing no longer blurs a good one. On a two-night Pleiades combine the stars came out 22% narrower, with the same noise.
  • Star colours survive the JPEG. The JPEG used to store colour at half resolution, which washed out the colour of small stars; it now keeps it in full (files about a fifth larger).
  • Galaxies keep their faint outskirts. The galaxy look no longer clips the faint outer disk and arms to black; half the sky still stays black.
  • Lossless copies of the final image: tick Also save in the app (or --export png,png16) for a PNG without JPEG compression, and a 16-bit PNG for further editing in another program without banding.
  • One line in the log about dark scaling instead of the same note over and over.

2.14 23 October 2026

2.14.0 23 Oct

  • Learned noise reduction for nebulae and star fields, chosen automatically on Origin data: much cleaner skies and more faint structure, with stars and colours kept as they were. Galaxies keep the learned deconvolver; --denoiser wavelet brings back the previous look.
  • A stretch that finds your target (--stretch object, also in the app's re-stretch menu): it brightens a small or faint galaxy from its own core rather than the whole frame, at the cost of a grainier sky. Nebulae and clusters look the same as before.
  • Cleaner multi-night combines (--merge-consistency, opt-in): something only one night shows, such as a satellite glint or a hot-pixel cluster, is left out; everything the nights agree on is kept.
  • AAVSO reports (--aavso-report): variable-star light curves in the format AAVSO's WebObs accepts, calibrated on AAVSO's own comparison stars.
  • See the difference: the website now shows ten sessions side by side, the Origin's own stack against OriginStack.
  • Support OriginStack: a link to the project's Ko-fi page in the app and on the website. It opens in your browser; the app sends nothing.

2.13 22 October 2026

2.13.0 22 Oct

  • A redesigned app. Pick what you imaged from picture cards, choose Full quality or Quick look, and see a summary of the run before it starts. Report a problem fills in a GitHub issue for you to review and send.
  • Learned star removal (experimental, --remove-stars-method nn): trained on Origin stacks, it also takes out the halos and diffraction spikes of saturated stars.
  • Comets that work. The comet is found by how it moves against the stars, the comet-aligned image keeps the field's rotation corrected, and the comet + stars image shows one head, however far the comet moved. When a comet is too faint to find, it says so instead of aligning on a star.
  • More reliable multi-night stacks. One bad or off-centre night no longer spoils the combine, the result keeps its sky coordinates, and --from-stack on it uses the run's settings.
  • Better-looking results: bright cores (Orion, the Ring Nebula, through the Nebula filter too, globular clusters) keep their structure, planetary nebulae keep their colours, Milky Way fields keep their glow and dark nebulae, and galaxies from bright-sky nights lose their pink corners.
  • Cleaner backgrounds: no dark holes beside bright stars (Mizar and Alcor), no coloured blobs around nebulae (the Pleiades, the Crab), no bright column through faint galaxies (the Antennae), and galaxy mode protects the galaxy rather than a bright star next to it.
  • Targets named the Origin way are recognised: Duck Nebula (Thor's Helmet), Cone, Pacman and Medusa Nebulae, Fornax A, Markarian's Chain, "Messier 101" and more, so they get their target-specific settings.
  • A portable Windows exe: one file that runs from any folder or a USB stick, no install.
  • Mosaics. Tile sessions from the Origin's Mosaic Mode are recognised and stitched into one image, from the Origin's own tile layout when it is present, with brightness and gradients matched across every overlap. Works in the packaged app with no extra software.
  • Faster. The first phase, which processes every frame, is about 35-40% faster: a whole 158-frame run went from 2m26 to 2m06 on an 8-core laptop, with an identical result.
  • Dither detection: the log and the stack's header say whether a session was dithered.
  • Other cameras on the Origin platform are recognised; learned deconvolution is chosen automatically only for the camera it was trained on.
  • Smoother backgrounds in frame-filling nebulae, other programs' stacks in a session folder are skipped, and calibration frames from more capture programs are recognised.

2.12 16 October 2026

2.12.0 16 Oct

  • Learned noise reduction and deconvolution (--denoiser nn, --deconvolve nn): small neural networks trained only on real Origin sessions, run on your own computer. The deconvolver makes stars 8-18% narrower and removes the noise, and was checked not to invent stars or detail. See learned methods.
  • Sharper galaxies by default. For Origin galaxy sessions the automatic settings now use the learned deconvolver; --deconvolve off keeps the previous result.
  • Separate stacks per filter. Nights shot with the Clear setting and with the Nebula filter are combined separately instead of averaged into one muddled stack.
  • Old galaxy stacks re-finish correctly with --from-stack, and bright stars no longer get a dark ring from star reduction.
  • A much larger website: how it works, a background page, a stretch gallery, an app guide, other cameras, a gallery and a command-line reference.

2.11 9–14 October 2026

2.11.9 14 Oct

  • Flatter backgrounds. Background extraction models every colour channel again; on a colour-calibrated stack it had quietly fallen back to a coarser method for green and blue. It is also twice as fast.
  • Faster re-finishing. --from-stack reuses its cached early steps even when you write to a new file name: 27 s down to 10 s per try on one stack.
  • Saved settings now keep skipped steps, and every preview follows the chosen stretch colour mode.

2.11.8 13 Oct

  • Re-stretch after a run. The app offers every stretch on the finished image; Apply to JPEG saves the one you like without re-processing.
  • Three new stretches: noise floor, OKLab and CLAHE. See the stretch gallery.
  • The preview stretch is per-channel by default again; --stretch-color preserve keeps colour ratios.

2.11.7 13 Oct

  • More stretches for faint nebulae: masked, multiscale and the SETI statistical stretch.
  • Gentler automatic local contrast on emission nebulae.

2.11.4–2.11.6 10–12 Oct

  • Big sessions on smaller machines. Frames are stored losslessly compressed when they would not fit in memory.
  • Large bright nebulae such as Orion show their faint outer parts and their core structure in the JPEG.
  • Already-debayered RGB FITS frames load again; the update notice shows reliably in the app.

2.11.0–2.11.3 9–10 Oct

  • Dutch for the app and the website.
  • A temp folder of your choice, checked for space before the run, and temporary files cleaned up after every run, even a cancelled or failed one.
  • Output can be a folder; the stack is named after the session and never overwrites an earlier one.
  • Very large sessions (850 frames) show progress instead of looking hung, and can be cancelled; closing the app always ends it cleanly.
  • Re-running a multi-night folder stacks the nights again instead of the previous result.

2.10 8–9 October 2026

2.10.2 9 Oct

  • Now under the GNU GPL v3. Still free to use, study, share and change; modified versions that are distributed must share their source too. Earlier releases remain under MIT.

2.10.0–2.10.1 8 Oct

  • Gaia answers from a local cache: re-runs and the next night of the same target colour-calibrate in milliseconds, and offline.
  • Colour calibration on hard fields: dense reddened nebulae and rich clusters whose bright stars are saturated now get a usable fit, and a fit that is too scattered is skipped rather than applied.
  • Seamless multi-night combines: no session edges, no red rims, white saturated stars.
  • --use-gpu was four times slower than the processor; now it matches it.

2.5–2.9 5–8 October 2026

2.9.0 8 Oct

  • Seven more languages for the app and the website: German, Spanish, French, Italian, Brazilian Portuguese, Japanese and Simplified Chinese.
  • A measured profile of the Origin's camera, for honest photometry error bars and colour calibration on sparse fields.
  • Overexposed subs (twilight, moonlight) are rejected; comet sessions blend and resume reliably.

2.8.0 7 Oct

  • A much smaller download: the native module went from 26.6 MB to 2.7 MB with identical results.
  • This website.

2.7.0 7 Oct

  • A macOS app for Apple silicon and Intel.
  • Cleaner skies and crisper galaxy arms: local contrast no longer adds grain to the sky.
  • Multi-night folders pool into one deeper stack when the rotation allows; live stacking follows field rotation.
  • --full-field keeps the edges the normal stack crops away.

2.6.0 6 Oct

  • "What did you image?" picture cards and Full quality / Quick look in the app, with a summary of what Start will do, a description under every setting and a settings search.
  • Small faint targets render on a clean, dark sky; bright stars are no longer blue discs.

2.5.0 5 Oct

  • True star colours: Gaia colour calibration on by default.
  • Star reduction that narrows stars instead of blurring them.
  • Large galaxies no longer come out as a red slab when they cover much of the frame.

2.4 2 October 2026

2.4.0 2 Oct

  • Proper image coaddition, on by default: sharper stars at no cost in noise.
  • A built-in plate solver: about a second per solve, no account, offline once the area is cached.
  • --from-stack: re-run only the finishing steps on an earlier stack.
  • Photometry error bars from a measured noise model.

Older releases are in the changelog and on the releases page.