Dark frames show a wavy pattern

[rohanpai]

I am using ASI1600mm and captured dark frames at 300sec and camera cooled to -1C. When stretched, the frame shows a wavy pattern from top right corner.

Does this look like a light leak?

[Stuart1971]

Yes, that looks like light leak to me….👍🏼

[tomato]

Agreed, it does look like light leak to me, but I’m surprised there is no amp glow showing on a 300 sec ASI1600 dark.

[david_taurus83]

59 minutes ago, tomato said:

Agreed, it does look like light leak to me, but I’m surprised there is no amp glow showing on a 300 sec ASI1600 dark.

It's probably there but if it's a light leak it's probably been stretched to a median value. Darks are usually stretched hard to give a visual appearance. 

@rohanpai did you take the darks with the camera on the scope?

[vlaiv]

3 hours ago, tomato said:

Agreed, it does look like light leak to me, but I’m surprised there is no amp glow showing on a 300 sec ASI1600 dark.

It won't show if light leak is strong enough compared to amp glow (and it does appear to be as there should also be noise visible in 300s -1C exposure - but there is none showing - it is too faint compared to light leak).

[rohanpai]

On 17/05/2022 at 18:39, david_taurus83 said:

did you take the darks with the camera on the scope?

hi @david_taurus83 - yes, i took this with the camera on the scope. I suspect there was light leak from near the OAG and I was taking these darks in daylight. I took darks again last night and they don't show this pattern anymore.

Edited May 19, 2022 by rohanpai