OwlPlot Stacker support
One clean stack,
and a real reply.
Answers for the Mac and Windows app are below. If yours is not, use Send Feedback in the app, or write to us: tell us your camera and what you were stacking.
Shooting
What to bring home from the night
- How many frames should I shoot?
- Ten to twenty of the sky, all at the same settings, from the same tripod position. Noise falls with every frame you add: sixteen frames are about four times cleaner than one. Add three to ten frames focused on and exposed for the foreground if you want sharp trees or land, and ten to fifteen lens-cap darks at the same ISO and shutter as the sky.
- Why are my stars short lines instead of points?
- The exposure was longer than the NPF limit for that lens, so the stars moved during each frame. Stacking cannot undo it: it averages trailed stars into trailed stars. Shorten the exposure and raise the ISO, open the aperture, or zoom out. The OwlPlot phone app works out the limit for your lens before you go out.
- Do I need dark frames?
- No, but they help: they remove hot pixels and warm patches the sensor adds by itself. Shoot them with the lens cap on, at the same ISO and shutter speed, at the end of the session. Leave them in the night’s folder; the Stacker recognises them and uses them without being picked.
- Can I use a shot plan from my phone?
- Yes. In OwlPlot on your phone, open the plan and share it as a plan file for the Stacker, then open that .owlplan file in the Stacker with the night’s folder. Sets shot during the plan come first, and the notes compare what you shot with what you planned. The plan never changes how a set is stacked.
Cameras and files
What it reads, and what it writes
- Will it open my camera’s raw files?
- Most raw files from Canon, Nikon, Sony, Fujifilm, Panasonic and Pentax open, as do standard DNG raws from any camera. Exported 16-bit TIFFs, PNGs and JPEGs can be stacked too. The cameras we have checked, and which of them have measured color, are listed on the supported cameras page.
- Which files does it not read?
- Olympus and OM System compressed ORF raws; Nikon High Efficiency raws (set the camera to Lossless compressed or Uncompressed instead); Canon sRAW and mRAW (shoot full-size RAW); and DNGs an editor has already processed, such as Lightroom’s Enhanced or denoised DNGs. Frames like these are marked Not supported and left out of the stack.
- Where are my stacks saved?
- In an “OwlPlot Stacks” folder inside the folder you opened. The stacked file is never changed by the develop dials; Export JPEG or Export 16-bit TIFF writes a separate, developed copy at full resolution.
- Can I finish the edit in Lightroom?
- Yes. Turn on Also save a DNG in the stack settings and the stack is written a second time as a linear DNG, which Lightroom and other raw editors open like a raw file, with their own white balance, profiles and noise tools. In Apple Photos and Preview a DNG’s deepest shadows can look crushed; raise Shadows or Blacks.
- The colors look a little off
- Cameras with measured color open in the camera’s own colors and white balance. Others get a close, general color: natural, not exact. Fine-tune it with Temperature and Tint, or use Match My Camera’s Colors in the Stack menu, which measures your camera from daylight photos shot as RAW + JPEG.
Results
When a stack is not what you expected
- Why was a frame left out?
- Every frame is measured and compared with the rest of its set, and the reason is shown on it: Trailed (wind or a knock), Soft (dew or focus drift), Cloud? (far fewer stars), Bright sky (headlights, a torch or dawn) or No stars. In Pro mode these only suggest; you decide what to stack.
- A frame is skipped because it did not align
- It has too few stars in common with the others: cloud, a moved camera, or a very different exposure. Leave it out.
- My stars are soft
- Usually dew on the front of the lens or focus drifting as the night cools. A lens heater strip prevents dew, and checking focus every hour handles the drift. Focus on a bright star with live view magnified to 10×; autofocus rarely works in the dark and infinity marks are not exact.
- The trees or ground are blurred
- The sky and ground were not separated well. Paint sky or ground with the mask brush over the suggestion and stack again. A foreground series, a few frames focused on the land, gives the sharpest ground.
- There is a glow or a color cast across the sky
- Remove light pollution fits the smooth glow towns put into the sky and subtracts it, keeping the Milky Way and the stars, and leaves the ground alone. Turn it off for skies without a glow or for very wide panoramas.
Mac and Windows
Where it runs, and buying it
- What does it run on?
- macOS 26 or later on a Mac, and Windows 10 (version 1809) or later on Intel, AMD or Arm PCs. Both versions stack the same way.
- Reading the frames never finishes (Mac)
- macOS asks once whether the app may read files on an external drive, and the question can be hidden behind other windows. Allow it, or grant access in System Settings › Privacy & Security › Files and Folders.
- Is there a free trial?
- The Microsoft Store version has a 7-day free trial. Purchases, trials and refunds are handled by the Microsoft Store and the Mac App Store, so a refund request goes to the store you bought from.
- Does one purchase cover both Mac and Windows?
- No. The Mac and Windows versions are sold by different stores, so each is its own purchase.
- How do I install it on a new computer?
- Sign in to the same store account and download it again from your purchases: the Mac App Store on a Mac, the Microsoft Store library on Windows. There is nothing to pay twice and no licence key.
- Does it upload my photos?
- No. Stacking, checking and editing all run on your computer, and the app makes no connection of its own. There is no account and no analytics. Feedback is an email you write and send yourself.
Still stuck?
Send Feedback in the app opens an email with the app version and the last lines of the stacking engine already in it, which is usually enough to find the problem.
Email support