Go Back   IceInSpace > Equipment > Equipment Discussions

Reply
 
Thread Tools Rate Thread
  #1  
Old 10-08-2022, 08:10 AM
Fluffyllama95 (Della)
Registered User

Fluffyllama95 is offline
 
Join Date: Feb 2022
Location: Tasmania
Posts: 15
Dark streaks ruining photos

Hey Guys! Need some help - I purchased my self an asi air plus. Everything is working great - guiding, polar alignment etc! I did a few test shots and noticed there are black streaks on the screen. It ruined my whole imaging session.
2 nights ago I used my laptop and sharpcap and it was fine! I cant see any dust specs. Its only when plugged into the asi air and capturing.
I was using the internal mmc of the asiair to save my captured photos.
I thought stacking flats and darks might fix it but nope!
Ive checked the sensor and the lens for dust but it all looks fine!
Any Ideas?
Gear:
Redcat 51
ZWO ASI533mc PRO
Here's 40 min worth of lagoon and trifid to give you an idea of what I'm talking about.
Attached Thumbnails
Click for full-size image (lagoon.jpg)
188.6 KB107 views
Reply With Quote
  #2  
Old 10-08-2022, 09:12 AM
iborg's Avatar
iborg (Philip)
Registered User

iborg is offline
 
Join Date: Feb 2015
Location: Lynbrook, Australia
Posts: 611
Dark matter?
Reply With Quote
  #3  
Old 10-08-2022, 09:19 AM
Nikolas's Avatar
Nikolas (Nik)
Dazed and confused

Nikolas is offline
 
Join Date: May 2012
Location: Melbourne
Posts: 3,253
too dark to see anything what are we supposed to be looking for? can you stretch the image so we can have a better look?
From brightening my screen to max it looks like dirt streaks on the imaging train. Never experienced an issue with the asiair like that. Seems like one bad image may be causing the weird artefacts, check all you images first to see if one is out badly.
Reply With Quote
  #4  
Old 10-08-2022, 09:48 AM
rustigsmed's Avatar
rustigsmed (Russell)
Registered User

rustigsmed is offline
 
Join Date: Mar 2012
Location: Mornington Peninsula, Australia
Posts: 3,950
looks like smudges/marks somewhere in the imaging train.
Reply With Quote
  #5  
Old 10-08-2022, 10:34 AM
middy's Avatar
middy
Registered User

middy is offline
 
Join Date: Feb 2006
Location: Brisbane
Posts: 655
My first thought when I looked at the image was that the streaks are all the same in length, shape and direction. They look like dust donuts that have slowly shifted across your image during the run. That to me screams out bad polar alignment, but you said your polar alignment was great so I'm at a loss.

Are you absolutely sure the polar alignment is good? Comparing the first sub and the last sub, did the stars shift a lot between the two?
Reply With Quote
  #6  
Old 10-08-2022, 10:38 AM
Fluffyllama95 (Della)
Registered User

Fluffyllama95 is offline
 
Join Date: Feb 2022
Location: Tasmania
Posts: 15
I used the inbuild polar alignment with asi air plus and I even did it 3 times. I was so close to perfect according to that. when i slewed to my target it was bang on centre. I'm assuming my polar alignment was perfect. I usually use the synscan controller. Ive stretched the image to really show how many marks their are.
bare in mind when using sharp cap and my laptop to take exposures i have zero issues.
Attached Thumbnails
Click for full-size image (lagoon low .jpg)
194.9 KB54 views

Last edited by Fluffyllama95; 10-08-2022 at 10:49 AM.
Reply With Quote
  #7  
Old 10-08-2022, 10:43 AM
middy's Avatar
middy
Registered User

middy is offline
 
Join Date: Feb 2006
Location: Brisbane
Posts: 655
Ah, OK. I have no experience with the Asiair plus or its polar alignment routine.
The other possibility is something flexing or moving during the run. As a mater of interest, can you post your first and last sub?
Reply With Quote
  #8  
Old 10-08-2022, 10:43 AM
rustigsmed's Avatar
rustigsmed (Russell)
Registered User

rustigsmed is offline
 
Join Date: Mar 2012
Location: Mornington Peninsula, Australia
Posts: 3,950
a single sub uncalibrated rather than a stack would make it a bit easier to find the cause
Reply With Quote
  #9  
Old 10-08-2022, 10:45 AM
Dave882 (David)
Registered User

Dave882 is offline
 
Join Date: Nov 2020
Location: PADSTOW
Posts: 2,052
I would check through all of your individual subs. AlASIAIR live stacking doesn’t do a very good job at eliminating poor subs so sometimes it tries to integrate these into the final stack and can cause big problems like this
Reply With Quote
  #10  
Old 10-08-2022, 11:56 AM
Fluffyllama95 (Della)
Registered User

Fluffyllama95 is offline
 
Join Date: Feb 2022
Location: Tasmania
Posts: 15
First and Last frames unstretched

here are the 2 individual frames if this helps
Attached Thumbnails
Click for full-size image (lagoon first.jpg)
163.6 KB89 views
Click for full-size image (lagoon last.jpg)
163.6 KB68 views
Reply With Quote
  #11  
Old 10-08-2022, 12:07 PM
Dave882 (David)
Registered User

Dave882 is offline
 
Join Date: Nov 2020
Location: PADSTOW
Posts: 2,052
Quote:
Originally Posted by Fluffyllama95 View Post
here are the 2 individual frames if this helps
Well you can definitely see them there too… mate that’s a head scratcher!!
And I’m assuming the marks don’t show up on your flats as well? Maybe post your flat frame here too if you have it…
Reply With Quote
  #12  
Old 10-08-2022, 12:25 PM
Fluffyllama95 (Della)
Registered User

Fluffyllama95 is offline
 
Join Date: Feb 2022
Location: Tasmania
Posts: 15
flat frame

flat frame
Attached Thumbnails
Click for full-size image (flat frame.jpg)
137.3 KB65 views
Reply With Quote
  #13  
Old 10-08-2022, 12:27 PM
carlstronomy (Carl)
Registered User

carlstronomy is offline
 
Join Date: May 2012
Location: Brisbane
Posts: 442
Not sure if this helps, but I had donuts not smudges on my images last week. These did not show up on flats, only on my lights. It was dust on the sensor of the camera, a good clean fixed it up. I also could see nothing visually, it does not take much at all to make a huge imprint on your results.
Reply With Quote
  #14  
Old 10-08-2022, 12:53 PM
Dave882 (David)
Registered User

Dave882 is offline
 
Join Date: Nov 2020
Location: PADSTOW
Posts: 2,052
Quote:
Originally Posted by Fluffyllama95 View Post
flat frame
A stretch of your flat frame reveals a few dust bunnies. That's not a problem, except for the fact that I can see these corresponding dust bunnies overcorrected in your stretched image in post #6. This tells me that your flat maybe isn't calibrating correctly - possibly due to your flat being too bright? I'm not familiar with your camera or ota so someone else may be able to give some more specific advice.

If it were me, I'd just start from scratch the next clear night (clean everything again, new calibrations and data) and see if it gives the same issue again.
Attached Thumbnails
Click for full-size image (flat frame stretch.jpg)
201.4 KB43 views
Reply With Quote
  #15  
Old 10-08-2022, 12:57 PM
Dave882 (David)
Registered User

Dave882 is offline
 
Join Date: Nov 2020
Location: PADSTOW
Posts: 2,052
Quote:
Originally Posted by carlstronomy View Post
Not sure if this helps, but I had donuts not smudges on my images last week. These did not show up on flats, only on my lights. It was dust on the sensor of the camera, a good clean fixed it up. I also could see nothing visually, it does not take much at all to make a huge imprint on your results.
Trying to image through high cloud or fog will do that! The illumination is different in those frames so the dust bunnies are more pronounced and will show in your calibrated stack.
Reply With Quote
  #16  
Old 10-08-2022, 12:59 PM
glend (Glen)
Registered User

glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 7,033
What do your Bias and Darks look like?
It seems the stars are appearing through your streaks. Looks like an optics aberration.
Reply With Quote
  #17  
Old 11-08-2022, 11:08 PM
barx1963's Avatar
barx1963 (Malcolm)
Bright the hawk's flight

barx1963 is offline
 
Join Date: Nov 2008
Location: Mt Duneed Vic
Posts: 3,978
I have had similar things. Usually getting too close to the moon when it is fairly bright. Looking on Sky Safari, that would appear to be the case. Not sure why this happens, but try imaging well away from the moon to see if problem persists!

Malcolm
Reply With Quote
  #18  
Old 17-08-2022, 04:59 PM
TeamG (Glenn)
Registered User

TeamG is offline
 
Join Date: Dec 2020
Location: Canberra
Posts: 9
What are you stacking with, maybe a different mode will help. Weird though, looks like you have had worms on the screen...
Reply With Quote
Reply

Bookmarks

Tags
asiair, astrophotograhy, help please

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:00 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement