Share:
Notifications
Clear all

MAY 4 2026: APP 2.0.0-beta44 has been released !

New improved internal memory controls should now work on all computers

May 1 2026: APP 2.0.0-beta43 has been released !

Improved internal memory controls (much more stable and faster on big datasets), fixed CPU image viewer, fixed Narrowband extraction demosaic algortihms.

Apr 29 2026 APP 2.0.0-beta42 has been released !

New improved Normalization engine, Fixed random crashes in integration, fixed RGB Combine & Calibrate Star Colors, fixed Narrowband extraction algorithms, new development platform with performance gains, bug fixes in the tools, etc...

Apr 14 2026: Google Pay, Apple Pay & WeChat Pay added as payment options

Update on the 2.0.0 release & the full manual

We are getting close to the 2.0.0 stable release and the full manual. The manual will soon become available on the website and also in PDF format. Both versions will be identical and once released, will start to follow the APP release cycle and thus will stay up-to-date to the latest APP version.

Once 2.0.0 is released, the price for APP will increase. Owner's license holders will not need to pay an upgrade fee to use 2.0.0, neither do Renter's license holders.

 

1-star registration, local normalization rejection - interesting star trails

2 Posts
2 Users
0 Reactions
3,515 Views
(@tomkrajci)
Main Sequence Star
Joined: 4 years ago
Posts: 14
Topic starter  

Attached is a stack of 55 images of comet C/2019 L3 ATLAS from two nights ago.

I used 1-star registration, and also local normalized rejection during integration.

2022 03 24 C2019 L3 ATLAS St 1

Note that the faintest background stars are trailed, which makes sense because the 1-star registration data showed that the comet drifted about five pixels (in the X direction, zero rate in Y direction) during the imaging run. But the brighter stars are not trailed at all.

I presume this is a feature of local normalized rejection?...it is only invoked above a certain threshold that is defined by the local background level?

Anyway, I just wanted to share this result. (When I first looked at the image I knew something was different, but it took me a bit of time to realize the difference in bright/faint stars that did/didn't trail.)



   
ReplyQuote
(@wvreeven)
Quasar
Joined: 8 years ago
Posts: 2134
 
Posted by: @tomkrajci

But the brighter stars are not trailed at all.

It is difficult to see with such a strongly compressed image, but the bright stars are trailed as well. Compared to the displayed size of the stars, however, the trailing of the bright stars is much less noticeable than that of the faint stars.



   
ReplyQuote
Share: