Advise please

[Anthony1979]

please can someone help me out..... why are my flats doing this to my image

every time i add my flats i get this black circle in the middle of the image, ive spent all day trying to figure out why and got no where

PLEASE HELP

[Anthony1979]

this is a image of just lights

[michael8554]

How are you taking the Flats, what Exposure are they?

What does you Flat look like ?

Michael

[Anthony1979]

The flats are 1sec 40 of them and i used led tracing pad with a4 paper ISO 400 same as lights

[HunterHarling]

Posting the flat would be helpful. Also, are you calibrating both the flat and light with darks? I ran into lots of issues when I didnt.

[michael8554]

Need to see a Flat. 

How did you arrive at 1 second exposure?

Michael 

[carastro]

More importantly, what is your histogram like with your flats, can you possibly post up a screen grab of single flat histogram, or otherwise what ADU is it?

Carole  

[Anthony1979]

Ive deleted everything i stacked in frustration.... So im re stacking again...

[Anthony1979]

1 hour ago, carastro said:

More importantly, what is your histogram like with your flats, can you possibly post up a screen grab of single flat histogram, or otherwise what ADU is it?

Carole  

My histogram was half way

[Anthony1979]

2 hours ago, michael8554 said:

Need to see a Flat. 

How did you arrive at 1 second exposure?

Michael 

I not to sure... 

[Anthony1979]

The camera was a nikon d3500 if that helps

[michael8554]

1 hour ago, Anthony1979 said:

Ive deleted everything i stacked in frustration.... So im re stacking again...G uh

You don't need to restack, just post one of your flats. 

Or you have deleted them, so you can't restack, they'll be in your PC Trash Can. 

Michael 

[scitmon]

2 hours ago, Anthony1979 said:

The camera was a nikon d3500 if that helps

1 second seems a little long for a DSLR to me, I guess it depends on your light source, I could be wrong.  Did you use the AV mode (I assume Nikon cameras have this too?)

[Anthony1979]

7 hours ago, michael8554 said:

You don't need to restack, just post one of your flats. 

Or you have deleted them, so you can't restack, they'll be in your PC Trash Can. 

Michael 

In getting start in imaging theres a post PROBLEM HELP... Ive put a tiff of my stacked flats and stacked lights

[happy-kat]

It was a single flat file please not the stack

[Anthony1979]

5 hours ago, scitmon said:

1 second seems a little long for a DSLR to me, I guess it depends on your light source, I could be wrong.  Did you use the AV mode (I assume Nikon cameras have this too?)

I was told try to get above a second... Ive tried the aperture mode but wont take picture so i use the manual 

[Anthony1979]

3 minutes ago, happy-kat said:

It was a single flat file please not the stack

You want a single image of the flat straight from the camera 

[happy-kat]

That was what a poster asked for above please.

You may need to zip it to add it.

Edited April 23, 2020 by happy-kat