TheSkySearchers-Welcome!

Recently I have noticed all of my images have a 'glow' on the right hand side.

I suspected the calibration frames so I processed it with no calibration and the glow was still there if not worse

Now granted the master dark was a 300 second duration and had to be 'optimized' when applied to the 180 second light frames. The darks were quite recent. I don't have a 180 sec 139/21 dark … yet.

Still I don't think that a corresponding dark is going to solve this problem and frankly suspect the camera. But I could be wrong.

I also thought it might have something to do with the narrow band filter so I swapped it out for the lum / ir cut filter and still have the same thing. With a brand new dust bunny to boot

Here is a more or less 'raw' image only stretched, no other processing was done.

Glow by Tom Whit, on Flickr

That of course is M45 or a piece of it. Pretty sure there is no red nebulosity around there.

Any ideas?

Nice wisps, if anything!

Thanks this was one panel of a 4 panel mosaic. But that glow will not play well with the gradient merge.

Here is another example. This time the lights were 300 second duration which matches the dark duration so no optimization.

This is in a much darker region of sky but you can see glow all around the image but most prominently to the right.

Example 2 by Tom Whit, on Flickr

ps I plan to crop and process this tiny very cool little galaxy I noticed it when doing a framing mosaic and the stock image showed a little galaxy in it. I will process it and put it through astrometry later. New thread in Images. Stay tuned

Yup, you got a "red" side and a "not red" side. In the past, we would almost always attribute this to amp glow, but nowadays, I don't know anymore. Following this thread closely.

Sorry you're having issues,
JT

Following along too, have you posed the question elsewhere?

I'd say amp glow too.
Or battery glow if your battery is to one side.
Try putting a spare battery in the fridge and swapping it in between frames.

No it's not battery glow. That much is for certain

This is an ASI1600mc cooled to -20C

I have not had a chance to ask elsewhere yet. Might post on the Pixinsight forums for some opinions.

BTW I looked it up and the warranty on the camera ran out in October.... of course.

I have a very similar glow on the right side of my ZWO1600 mono as well.
mine is two distinct areas of glow, but almost identical in size to yours.
I've learned to use PixInsight's dynamic background extractor to remove most of it. Darks don't touch it, whatever it is.
Good Luck!

There is some red/brown nebulosity there but it should not extend below the horizontal row of stars below the center, https://www.bing.com/images/search?view ... 2,6&sim=11

I have been doing a little research on this and it appears to be a common issue to the ASI1600 both the mono and osc.

One thing I have learned is that you should NOT calibrate dark frames as it tries to average out the background levels making things worse.

I made a new set of darks with the appropriate duration, offset, gain and applied those. It made a slight improvement as the darks did not have to be scaled but as mentioned darks dont seem to do much with it. Though I did one run without any calibration and it was horrible! So the calibration do help to some extent.

Thanks for the link Henk, I have never noticed that colored region in any image of M45 I have seen before. Maybe some of it is actual signal? Though it does not explain it showing up on the galaxy image.

I am going to shoot a new set of flats tonight since it will be cloudy anyhow and I need a fresh set for the UV/IR cut filter.

I will post back results afterwards.

Thanks for the help so far!

could be sky glow which is showing dominant in the lower signal area of the target.

I ran thru some of my recent 1600mc shots and do not see this color glow. So it is not generic to the camera, at least not mine. So, I am mystified and will follow your investigation closely in case this shows up in my camera. Of, course there is a lot of amp glow with this camera and this has been subtracted with darks in my shots, but I do not apply a bias cal to any of my cameras, haven't seen any advantage, only pain.

Clear skies,
Steve

yobbo89 wrote: ↑Thu Dec 05, 2019 6:30 pm could be sky glow which is showing dominant in the lower signal area of the target.

Why is it red?

Getting ready to collect the flats, then the flat darks. Another hour or two (after I put everything away).

Okay got a new set of calibrated flats to go with the darks I got yesterday.

Applied those and it is better, I 'think'.

A background extraction helps but still :p

New Calibration by Tom Whit, on Flickr

Now to try to put this mosaic together