Jump to content

sgl_imaging_challenge_2021_2.thumb.jpg.72789c04780d7659f5b63ea05534a956.jpg

Weird noise pattern created from black pixels


Recommended Posts

Hey everyone,

As the titel mentions, after stacking alot of photos from M31 taken over multiple nights at slightly different ISO and Exposure values i have noticed a specific noise pattern of black pixels only, which becomes much clearer after some slight edits in PS but can already be seen in the stacked image (I used DSS)... I've attached the image below and oversharpend so it can be seen clearly. Any ideas?

Many thanks!

Black pixals create specific noise pattern.png

Edited by astrobena
Link to post
Share on other sites
  • astrobena changed the title to Weird noise pattern created from black pixels
  • 2 weeks later...

Hi Astrobena,

Noticed you had no replies on this one, not sure why, however I think it would help if you included full details of the imaging set up from telescope to camera, settings for exposures, times, how many were stacked, ISO/gain, offset. It looks as if you are using DSS and PS? What were the stacking settings? What is the final outcome and problem? That will give people a better chance of understanding what is causing the issue. Does this issue occur in single subs, the stack, or just the end product? Currently its like saying my car won't go, why not? Need a little  more detail. Also good to attach the actual image with the issue so folks can look for themselves (some issues are down to the display screen being used and don't exist in the image itself. Probably the stack and your 'finished' image. I find peoples questions often lead me to the answer.

It is good to keep your stacks to single exposure lengths and ISOs - imagine trying to process a night time image and a daytime image. I used to do this but have learnt to just keep it to one set of settings, even though it pains me to disregard piles of data. You can combine data with different settings but do it as layers using masks - folks often do this with the bright core of the Orion nebula. Maybe 2 minute subs then 15 second subs for the bright core - process the 2 minute data for the bulk of the nebula, the 15 second data for the core then overlay the the core using a mask.

Alas I have no idea why that is happening but I sure I have seen it in my own images from time to time.

Good luck, hope someone picks this up.

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.