I want to share a recent enlightening with any Pixinsight users that might have noticed a similar issue as I was having.
When I first started using
PI about 9 months ago, after running the WBPP script to pre-process my data, the brighter stars were "square" or "pointed" looking.
It definitely looked like an anomaly to me. Possibly something wrong in my optical train. I was hesitant to post to the
PI forum because of my "newness", so I used
DSS to stack. In the
DSS stacks, the same "square" stars produced by
PI were nice and round. I did some researching and ended up changing some settings in
PI for preprocessing or just used
DSS for pre-processing.
Just recently, I started using a new scope (Sharpstar 61 EDPHII) with the same camera (ASI 533
MC-P) and reset the
PI WBPP script settings back to default. When I generated the first masterlight, I zoomed in and saw the same "square" stars again!
I prepared a masterlight with the WBPP defaults (with "square" stars), another masterlight with the modified settings that I had been using (only slightly "square" stars) and an Autosave.fit with
DSS to compare the three.
The WBPP masterlight with default settings had the "square" stars, but had obviously better quality (resolution) than the WBPP settings that had been using trying to minimize the "square" star effect. The
DSS autosave.fit had the nice round stars, but the resolution was the lowest of the three in the test.
I posted to the
PI forum and here is the link in case you are interested.
https://pixinsight.com/forum/index.php? ... ars.17172/
Here is the comparison image that I submitted to the
PI forum (I don't think that it can be viewed unless you are logged into the forum). This is a 2x zoom in on a part of the M31 dust lanes with only a screen stretch with no processing.
The
PI WBPP with defaults is the image on the left (Square stars). The
PI WBPP with the settings that I have been using to get "rounder" stars is in the middle. The
DSS stack is on the right.
I might be the only person that has had/noticed this issue. But just in case you might have noticed a similar issue and were not sure why, here you go.
You might be thinking "Man, what a bonehead", but live and learn!
Jim
Scopes: Explore Scientific ED102 APO, Sharpstar 61 EDPH II APO, Samyang 135 F2 (still on the Nikon).
Mount: Skywatcher HEQ5 Pro with Rowan Belt Mod
Stuff: ASI EAF Focus Motor (x2), Orion 50mm Guide Scope, ZWO 30 mm Guide Scope, ASI 220mm min, ASI 120mm mini, Stellarview 0.8 FR/FF, Sharpstar 0.8 FR/FF, Mele Overloock 3C.
Camera/Filters/Software: ASI 533 mc pro, ASI 120mm mini, Orion SSAG, IDAS LPS D-1, Optolong L-Enhance, ZWO UV/IR Cut,
N.I.N.A., Green Swamp Server, PHD2, Adobe Photoshop CC, Pixinsight.
Dog and best bud: Jack
Sky: Bortle 6-7
My Astrobin:
https://www.astrobin.com/users/Juno16/