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2023-04-17: APP 2.0.0-beta17 has been released !

RAW support for camera color matrix with Bayer Drizzle integration, fixed couple of image viewer issues.


We are very close now to  releasing APP 2.0.0 stable with a complete printable manual...


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APP fails to detect / register stars

3 Posts
3 Users
Main Sequence Star
Joined: 5 years ago
Posts: 15
Topic starter  


(I actually solved this problem. So it's just an FYI)

Last night I shot Abell 33 from my Bortle 8 yard.
ASI2600MC and RC6 at 950mm f6. Antlia ALP-T filter.
It's a low target in my location (50dgrs max).
The lights were noisy.

Integrated with APP with my usual (standard) settings.
APP didn't report any errors but failed to detect/register stars.
The final integration was a mess.
Tried different Registration settings - didn't help.

I was puzzled since it never happened to me before.
PI integrated the same set of lights without a problem.

To tell the long story short:

-- switching from Adaptive Airy Disk to Adaptive Edge helped
but then I still couldn't extract Ha/OIII

-- then I discovered the Cosmetic Correction options which I never used before.

Enabled all three of them with defaults and it worked with the Adaptive Airy!

I am glad I was able to resolve this.

Universe Admin
Joined: 6 years ago
Posts: 3551

Hi @maxthebuilder,

Thank you very much for sharing this.

In the 2.0.0 beta's several things were improved in star analysis to make it more robust for more datasets. In your case, you do not need to enable cosmetic correction to make it work, allthough if it does that is fine. But in 3) Analyse Stars, you would need to increase the new cosmic ray/noise reducer a bit. The registration would fail if APP sees noise or cosmic rays as stars. By increasing the cosmic ray /noise reducer lower-limit area size to 6-10, probably all will work fine ;-). This is more efficient than increasing the cosmetic correction I think in terms of speed. In cosmetic correction, hot pixels would be removed (thus noise) so it makes it very likely that your registration issue was caused by noise in combination with small stars in your data as well.


Main Sequence Star
Joined: 5 years ago
Posts: 24

I continue in this thread so as not to do the same thing in duplicate.
I had indeed enabled the "cosmic ray / noise reducer" option but the result had been the same.
What had not occurred to me was to increase its value.
I have repeated the process again with "lower-limit area size" equal to 8 and the result, now yes, has been as expected.
Thanks, Mabula and Vincent.