Samyang 135mm(Nikon lens) + ASI1600MM-cool

kunhee

There is a problem with the picture taken last weekend.

I set it up like below.
Samyang 135mm(Nikon mount) + Nikon adapter for EFW + ZWO EFW(7*36) + ASI1600MM-cool
(below : just image file)
https://drive.google.com/file/d/1PiApVBNQJCa3Ai6fh1YfDeV0_zDaZ4rJ/view?usp=sharing
Only the lens is different from the ones above(URL)

But when I saw the picture I took, it came out as below.
(below : just image file)
https://drive.google.com/file/d/1bQhIvnY9VtLbUbx0aP8bmT77sMU3hXUz/view?usp=sharing
Filter : Ha / sub : 300s

The edges of the picture are bright....

I don't know why this is happening.
I want to get help from you.

Thank you!

gnyman

Interesting, what you experience - I got the exactly same outfit and my corners are not like yours - did you substract flats which had been not correct for that optical layout?

kunhee

gnyman
I didn't take out flat from this picture.
This picture is not pre-processed.
I'll take a picture of the flat, and then I'll try to remove the flat from the picture.
Thank you.

kunhee

gnyman
Did you get the normal picture after you took out the flat?

gnyman

kunhee even without flats, my pictures have not been that white at the borders.... I shall verify it in the next few days and let you know - if weather permits!

kunhee

gnyman If the weather is clear tomorrow night, I will go to test my equipment again. Thank you : )

kunhee

I solved the problem by extending the distance between the filter and CMOS.