remove light pollut...
 
Share:
Notifications
Clear all

2022-05-29: APP 2.0.0-beta2 has been released !

Release notes

Download links per platform:

windows 2.0.0-beta2

macOS x86_64 2.0.0-beta2

macOS arm64 M1 2.0.0-beta2

Linux DEB 2.0.0-beta2

Linux RPM 2.0.0-beta2

remove light pollution problem


(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

Beginner's problem.  I use the workflow in Christian Sasse's tutorial. I have successfully produced several really good images so far. I recently imaged M51 (lrgb). All of the blue frames were bad - the rest were quite good.  I went ahead and made a really nice image from the data I had. The next night, I reshot the blue frames with excellent results. I then loaded the good lrg images and the new good b images.  I combined rgb and had a really nice image.  When I started "remove light pollution", the image went completely white.  I have read about others having this problem. I tried adjusting the b, w, and st sliders. I was able to see my image, but I couldn't get it even close to what it looked like before starting light pollution removal. Any pointers would be greatly appreciated. And thanks to the developers of this software - I'm thrilled that I'm finally producing images after having no success with other programs!


ReplyQuote
(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Mmm, you calibrated all frames with the correct calibration files? It might be that dark or bias calibration is the issue in that case. Not sure, for that I would need to check myself with the original raw data and raw calibration files. If you want to upload a set (good versus the white version) I can give you the link.


ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

That would be great if you could take a look.  The only calibration frames I used were 15 darks.


ReplyQuote
(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Those may have an issue, could you just try without them to see if it happens again?


ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

 

 

I have another problem which is probably related. Took data on M82 last night. The good news is that only 2 out of 160 frames were not registered. However, when I combine LRGB there is a problem.  If I remove the luminance channel, the image is normal. When I add in the luminance channel, it's messed up. I'll attach screens shots of both.

Screen Shot 2021 03 09 at 11.17.38 AM

 

Screen Shot 2021 03 09 at 11.17.58 AM

ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

@vincent-mod I'll try that and let you know what happens.


ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

Indeed that did the trick.  What do you suppose is wrong with the darks?  I took them in between another imaging run and this one, with the same gain and exposure time.


ReplyQuote
(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Difficult to say, I just notice that when something is up with calibration, it usually are the darks. Could be a number of things, what settings do you use when making the dark and what do you do in APP itself?


ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

@vincent-mod Same settings as the imaging run. I follow Christian Sasse's workflow exactly - load the lignt frames, load the dark frames, then hit calibrate.  Correction - I hit "create masters and assign to lights"

This post was modified 1 year ago by Ed Wallace

ReplyQuote
(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Mmmm, maybe they weren't completely dark? Is the offset ok as well on them?


ReplyQuote
(@edwallace)
White Dwarf Customer
Joined: 1 year ago
Posts: 24
Topic starter  

@vincent-mod Lens cap on camera, camera inside thick black glove (outside at night).  I'm ashamed to say I do not know what offset is. I will learn about that tonight. Now I have to go to work. Thank you for taking the time to help.


ReplyQuote
(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

An offsets is a noise floor basically for the sensor (if I'm not saying this incorrectly 🙂 ). But those are for astro-camera's.

In your case, I probably would need to look at the dark itself. Light can still create an issue, might also come from within the camera even. No idea if that's the case for you of course. No light in the garden at night from neighbours?


ReplyQuote
Share: