Problems with SC4

A place to report problems and bugs in SharpCap
Forum rules


If you have a problem or question, please check the FAQ to see if it already has an answer : https://www.sharpcap.co.uk/sharpcap-faqs

Please also read about Troubleshooting USB Issues before posting.

*** Please do not post license keys - please report any problems with licensing to 'admin' by private message ***

Please include the following details in any bug report:

* Version of SharpCap
* Camera and other hardware being user
* Operating system version
* Contents of the SharpCap log after the problem has occurred.
[If SharpCap crashes, please send the bug report when prompted instead of including the log]
Post Reply
Lloyd69
Posts: 9
Joined: Tue Jan 04, 2022 6:01 am

Problems with SC4

#1

Post by Lloyd69 »

Hello Robin,
I have problems with SharpCap 4 which I don't have with version 3.2. I have tried to work with it a few times since I installed SC4 but quickly stopped because it didn't respond as I expected and I didn't want to waste the short time under a clear sky on experiments, so I'm always back to SC 3.2 swept.
Today I started again with SC4 and always had stripes in the first pictures. I started the live stacking several times and these stripes kept coming back as you can see on the screenshot.
Screenshot_5.png
Screenshot_5.png (902.39 KiB) Viewed 538 times
or this
Screenshot_4.png
Screenshot_4.png (802.04 KiB) Viewed 538 times
where do these stripes come from? I have no stripes in SC3.2 with similar settings.
Here is another picture which I took immediately afterwards with SC3.2 with the same basic settings. No stripes!
Screenshot_8.png
Screenshot_8.png (883.04 KiB) Viewed 538 times
I hope you can help me here.

Regards
Lloyd69
User avatar
admin
Site Admin
Posts: 13177
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: Problems with SC4

#2

Post by admin »

Hi Lloyd,

I think those are definitely coming from the banding suppression option - the threshold is too low, which means that some stars are being included in the calculations - these raise the average brightness of the image rows that they are in as far as the banding calculations are concerned, and then the suppression code tries to bring it back down to the average, leading to the dark bands aligning with the stars.

It's very difficult to tell the exact why of the problem, since you are using live stacking in all the screenshots, and banding suppression is something that is calculated on the image before it is stacked.

I would suggest a test with live stacking turned off, display histogram stretch reset to default and flats/darks disabled in both 3.2 and 4.0 to validate that the images (at source, when retrieved from the camera) are equally bright and whether or not adjusting the banding suppression strength and/or threshold affect them equally. If they do not seem to behave equally in that simple test then please let me know. If they do seem to work the same in that simple case, reintroduce darks, flats, stacking etc (one thing at a time) to try to find out what change introduces the problem.

cheers,

Robin
Post Reply