18 replies to this topic

[Aman Dude]

I made sure this thing was clean of smudges and dust spots. For some reason after DBE in PixInsight, It looks like this. What the heck could be wrong?

 

[rj144]

Did you take flats?

[Aman Dude]

Did you take flats?

No, I did not yet. This is some test data.

[rj144]

No, I did not yet. This is some test data.

Well, flats will fix that, so don't worry.

[Aman Dude]

Well, flats will fix that, so don't worry.

Will they fix the wavy vertical banding too? Or just the dust spots?

[rj144]

Will they fix the wavy vertical banding too? Or just the dust spots?

Did you take any calibration pics?  Is this one sub or a stacked sub?  If it's stacked what are the details?   Also, what are the details on a sub?

[sharkmelley]

Will they fix the wavy vertical banding too? Or just the dust spots?

Flats will fix the dust spots but they may not fix the wavy vertical banding.  It depends on the cause of the wavy banding.  For instance, my Sony A7S had green/purple vertical swathes that I was never able to calibrate.  Believe me, I tried everything.

[Chrisofweden]

In the past I imaged using an A7IIIR and even after correct calibration I would sometimes be left with this “striping” in my stacked image.
When the problem arose, I used a script in PI called “Canon Color banding” (or something like that).
It usually helped
Give it a try, it can’t hurt

/Chris

[Aman Dude]

Well, flats will fix that, so don't worry.

After Flats it still has issues:

[rj144]

After Flats it still has issues:

Screenshot 2024-04-22 090051.png

But they weren't taken or applied correctly or else you wouldn't see the dust motes.  Did you take bias?  

 

Again, is this a stack or a sub?  What's the details?

[Aman Dude]

But they weren't taken or applied correctly or else you wouldn't see the dust motes. Did you take bias?

Again, is this a stack or a sub? What's the details?

This was 600 30sec subs and I took the flats outside using a clear sunny sky and used 1/160 shutter for that, same for the dark flats and all at ISO 400. Stacked in Deep Sky stacker

[rj144]

This was 600 30sec subs and I took the flats outside using a clear sunny sky and used 1/160 shutter for that, same for the dark flats and all at ISO 400. Stacked in Deep Sky stacker

You mean in the middle of the day?  I never do sky flats, but I think everyone takes them at dusk or in the morning.  Is the striping in a single sub?

[bbasiaga]

This was 600 30sec subs and I took the flats outside using a clear sunny sky and used 1/160 shutter for that, same for the dark flats and all at ISO 400. Stacked in Deep Sky stacker

You need to be focused at infinity, and put something like a t shirt over the lens. Mid day in the sun 1/160 sounds way too long for a flat. The histogram should ideally be in the center, or just left if it.

Brian

[rj144]

You need to be focused at infinity, and put something like a t shirt over the lens. Mid day in the sun 1/160 sounds way too long for a flat. The histogram should ideally be in the center, or just left if it.

Brian

The focus should be close to infinity, but it should be exactly the same focus as the lights.

[Aman Dude]

You need to be focused at infinity, and put something like a t shirt over the lens. Mid day in the sun 1/160 sounds way too long for a flat. The histogram should ideally be in the center, or just left if it.

Brian

I did but still get the same kinda thing.

[DanMiller]

If the canon banding script doesn't clean them up, as another reply indicated. Sirill also has a script that is very good at correcting that type of banding.  Sirill is free.  Also, the GradiantCorrection process in Pixinsight cleans up a lot of my banding.  I image with an old Canon, so I have to clean up banding all the time. 

 

So, do your calibration frames.  Process in WBPP with everything, see if the banding is still bad.  And run the gradiantcorrection process.  If still have banding, run the canon banding script in pixinsight.  If still something left, then download Sirill and run it's banding script.  You will be surprised at the results.

 

Dan

Edited by DanMiller, 22 April 2024 - 08:35 PM.

[caspase888]

Were you able to resolve the issue?

You could refer to this as well:

https://www.markshel...d_polygons.html

[Robot00]

Were you able to resolve the issue?

You could refer to this as well:

https://www.markshel...d_polygons.html

According to https://www.markshel...ra_summary.html , Sony A7IV doesn't have "coloured polygons" issue.

[caspase888]

According to https://www.markshel...ra_summary.html , Sony A7IV doesn't have "coloured polygons" issue.

Great. Thanks for pointing this out.

This issue in SONY A7IV doesn’t occur when the lens corrections are switched off.

Thanks

Edited by caspase888, 06 December 2024 - 02:59 PM.