AkastroidComparison
Akastroid vs PixInsight
PixInsight has more depth than any other astrophotography program, and learning it well takes a long time. Akastroid does not replace it. This page lists what you get and what you give up.
The short answer
Buy PixInsight if you want to take each image as far as it will go, you have time to learn, and you want its masking. Nothing else I know of matches the masking.
Use Akastroid if what stands between you and a photograph is the learning curve, or if you have more data than processing time and want triage.
Use both if you already know PixInsight. Akastroid stacks a session in minutes and writes the integration unprocessed; you finish it where you are fluent. For most current PixInsight users that is the useful combination.
Where PixInsight is better
Masks. Range masks, luminance masks, star masks and PixelMath let a correction be applied to part of an image: the core stretched differently from the outskirts, noise reduction on the background only, sharpening confined to the structures that can take it. Akastroid's adjustments are global. This is the largest gap between the two.
Depth. Multiscale processing, mathematical morphology, wavelet-based tools, custom pixel arithmetic, full control of every stage. Akastroid has none of these.
Add-ons. BlurXTerminator and StarXTerminator plug into PixInsight, and I don't know of anything better at deconvolution or star removal. Akastroid's deconvolution is regularised Richardson-Lucy with a PSF measured from your own stars. It is automatic and included, and it is not state of the art.
Where they differ
| PixInsight | Akastroid | |
|---|---|---|
| Cost | Licence plus the usual paid add-ons | One payment, free tier, 14-day refund |
| Platforms | Windows, macOS, Linux | macOS, Windows and Linux (beta) |
| Time to a first image | Weeks to months | Minutes |
| Ceiling in expert hands | The highest available | Lower, and deliberately so |
| Masks and selective editing | yes, the main reason to buy it | no, adjustments are global |
| PixelMath and scripting | yes | no |
| Decides parameters from your data | no, you decide | yes, measured |
| Explains each decision afterwards | no | yes, with the number behind it |
| Frame rejection with a named fault | metrics, unlabeled | twelve measurements, fault named |
| Planetary and lunar video | no | yes |
| Exports an unprocessed integration | yes | yes |
| Runs entirely offline | yes | yes |
They answer different questions
PixInsight answers "how do I take this image as far as it can go". It assumes you want to learn processing, and it repays the effort.
Akastroid answers "I have a folder of frames and I would like a photograph". It assumes the processing is not what you came for. The decisions PixInsight asks you to make are measured instead: which frames to keep, which integration method, where the black point belongs, how hard to deconvolve, what the real colors are. The full sequence is written out step by step.
Both are reasonable things to want. The mistake I see most is buying the first when you wanted the second, going three months without an image, and giving up.
Clear nights cost more than licences
Finding out in March that January's data was unusable (dew on the second half, a focus shift, dithering that was never switched on) costs you the session, not an hour of processing. Grading that names the fault at import tells you what to change before the next clear night.
What Akastroid does not do
It has no masks, PixelMath or scripting, and a lower ceiling by design. If you need any of those, buy PixInsight.
The longer version of this comparison, covering Siril, AutoStakkert, RegiStax and WinJUPOS as well, goes further into the cases where the other tools win.
Questions
Can Akastroid replace PixInsight?
For a lot of people, yes; for the images PixInsight is famous for, no. The single largest gap is masking. PixInsight's range and luminance masks and PixelMath let you apply a correction to part of an image, and Akastroid's adjustments are global. Masks are much of what makes a competition image, and if your workflow depends on masks then Akastroid is not a replacement for the finishing pass.
How long does PixInsight take to learn?
Most people say months. That is not a criticism. The interface predates modern conventions, the documentation assumes signal processing vocabulary, and the depth that makes it worth learning also makes it slow to learn. For many people that is a fair trade. For others it is why they never get a first image.
Is Akastroid cheaper than PixInsight?
Yes, and the licence is only part of it. A working PixInsight setup usually includes paid add-ons (BlurXTerminator and StarXTerminator are the common two), which together cost more than the base licence again. Akastroid is one payment with a free tier and a 14-day refund; see the pricing page for the current figure.
Can I use Akastroid as a front end for PixInsight?
Yes, and for experienced imagers this is probably the most useful way to use it. “Save the stacked image, unprocessed” writes the integration before any stretching, color or sharpening is applied. Calibrate, grade, register and integrate in a few minutes here, then finish in the tool you already know. It also works as triage: a finished result in three minutes tells you whether a session is worth two hours.
Is BlurXTerminator better than Akastroid's deconvolution?
Yes. BlurXTerminator is better than regularised Richardson-Lucy with a measured PSF, which is what Akastroid runs. Akastroid's version is automatic, declines to run when it would do harm, and is included rather than bought separately. It is not state of the art.
Try it on a session you already have
Free, every feature, three free processing runs and one export to try it on. No account, and nothing leaves your computer.