Akastroid vs AutoStakkert

The short answer

Keep AutoStakkert if you are on Windows, you already have PIPP and RegiStax set up, and the workflow is not in your way. It costs nothing, it is superb at the one job it does, and swapping a working planetary pipeline for a new one buys you little.

Use Akastroid if you are on a Mac and tired of running Windows software under Wine, if you would rather not chain three programs per capture, or if you shoot deep sky as well and want one application for both.

What was actually measured

Both stacks of the same captures, unsharpened, compared at matched physical frequencies - so neither side is flattered by being on a finer grid - with each normalized against its own coarse-scale content.

• Detail. On a Saturn capture, ours carried 2.6x the power at 0.15 cycles per pixel, 7.3x at 0.20 and 10.8x at 0.25. The limb, which noise cannot flatter, measured 24.67 px against 26.00 - sharper. On Mars the limb was level at 4.00 px each, with 8-20% more energy at low and mid frequencies on our side.
• Noise. Binned to camera scale first, Saturn measured 27% cleaner on ours; Mars measured 79% cleaner on AutoStakkert's. Capture-dependent, in other words, and not a systematic advantage either way.
• A retraction. The first version of that noise comparison said "AutoStakkert is 56% cleaner", and it was wrong - per-pixel sigma on a 3.0x drizzle grid is lower than on a 1.5x one whatever the underlying noise, because neighboring pixels come from the same photons. The number changed when the ruler was fixed. It is here because a comparison page that only reports its wins is worth nothing.

The honest claim

Sharper than AutoStakkert on every capture tested, and cleaner on some. Not cleaner everywhere, and not a replacement for a Windows workflow that already works.

Three programs or one

The usual planetary chain is PIPP to center and crop, AutoStakkert to grade and stack, RegiStax or AstroSurface to sharpen. Each is good and each is a separate export, a separate folder and a separate set of settings to remember.

Akastroid does the three stages in one pass: frames are graded and located from where the planet actually is, stacked with multi-point alignment, corrected for atmospheric dispersion and sharpened per scale - with the sharpening strength measured from the stack rather than guessed with sliders. The same application also stacks deep-sky frames, which none of those three do.

Side by side

Questions

Is Akastroid better than AutoStakkert?

On the captures we have measured, Akastroid's integration is sharper on every one, and cleaner on some of them - not all. The comparison was made on the unsharpened stacks, at matched physical frequencies, with both binned to camera scale before noise was measured. On a Saturn capture ours measured 27% cleaner; on a Mars capture AutoStakkert's measured cleaner. So it is capture-dependent, and anybody who tells you one stacker is simply better than another on every target is not measuring.

Does AutoStakkert run on a Mac?

Not natively. It is a Windows program, and Mac users run it under Wine, CrossOver or a virtual machine - which works, and is one more thing to maintain. So is RegiStax, so is PIPP, so is WinJUPOS: the entire standard planetary chain is Windows-only, which is the real reason Mac planetary imagers go looking. Akastroid is a native Mac application on Apple Silicon and Intel, as well as Windows.

AutoStakkert is free. Why pay for anything?

If AutoStakkert plus RegiStax plus PIPP is working for you on Windows, keep it - that combination has produced most of the planetary images you have ever admired. The case for Akastroid is that it is one application instead of three, it runs on a Mac without Wine, and it also does deep sky. If you only shoot planets on Windows and are happy with the workflow, there is no argument here.

Do I still need PIPP?

Usually not. PIPP's common jobs - centering a drifting planet, cropping to the disc, converting between formats - happen inside Akastroid's planetary path: every frame is located from where the planet actually is before it is stacked, and the result is cropped to the disc.

Do I still need RegiStax?

Not for wavelets. Akastroid sharpens per scale after stacking, with the strength measured from the stack rather than set by six sliders. RegiStax has controls Akastroid does not expose, and we have not measured the two against each other - see the RegiStax comparison for what that does and does not mean.

The planetary workflow in detail is on the planetary page, and what replaces PIPP, AutoStakkert and RegiStax goes stage by stage. On a Mac, start with what actually runs on macOS - it is honest about the free tools that do. Download for Mac and try it on a capture you have already stacked - that is the only comparison that settles anything.