Which should you use?
Both turn planetary videos into sharper single images. PSS by Rolf Hempel is a Python desktop app with a mature, well-documented codebase. Eise.app runs in the browser, no install. Same core idea, different setup.
Short version: PSS if you're comfortable installing Python and want a hackable desktop app. Eise.app if you want to open a URL, drop a file, and be done.
| Planetary System Stacker | Eise.app | |
|---|---|---|
| Install | Python + dependencies | None, runs in browser |
| Platforms | Win, Mac, Linux (via Python) | Anything with a modern browser, mobile included |
| Source | Open source on GitHub | Open source on GitHub |
| Price | Free | Free |
| GPU acceleration | No (CPU only) | Yes (WebGPU when available) |
| Post-processing | Minimal, most users pair it with Registax | Built in (sharpening, colour, RGB alignment) |
| Learning curve | Steeper (Python setup + exposed knobs) | Guided flow, sensible defaults |
Eise.app owes real credit to Rolf Hempel and PSS. Studying PSS's implementation and Rolf's documentation shaped much of Eise.app's design. If you want to understand the algorithms, PSS on GitHub is still the best resource.
PSS fork with compatibility fixes. Upstream PSS (last release 0.8.22) hadn't been updated for newer Python and UI-toolkit versions, which made installing it increasingly awkward. Eise.app's author maintains a fork at github.com/timing/PlanetarySystemStacker with the following changes since 0.8.22:
pyproject.toml instead of setup.py).m4v video files for stacking--config_file CLI flag for headless and scripted runs.app bundle, so you can run PSS on a Mac without installing Python