Artifact in the picture but not in the flat frames.

3 replies104 views
inhuslight avatar
Hi everyone,

While taking pictures, I noticed a strange artifact on the subs. Blue circle with a green border. It was also visible after the meridian flip, but it moved from the position in the image compared to the before the flip. 

I noticed that I had a somewhat transparent stain on the filter, but I did not clean it. I suspect that this stain is the cause of this artifact. I was hoping that calibrating with flat frames would remove this artifact, but that didn't happen. No stain is visible on the flat frames. I have not yet had a chance to clean the filter and try again to confirm this assumption.

Has anyone had a similar case or has more knowledge about this? If it's not this stain, then I don't know what the problem would be because I've never had this kind of appearance in pictures before.

Attached is an integrated image and master flat frame.

Helpful Engaging
Tony Gondola avatar
It looks like your flat was taken with no filter so in that case, it's not going to tell you anything. You didn't say what kind of filter you're talking about but if you have a filter in your imaging train that shows a visible defect, I certainly wouldn't use it.
inhuslight avatar
I just noticed the same thing on a different spot in the picture. Now I have no idea what this could be. 

Flats where taken with the filter asswell. It is just a UV/IR cut filter hence I don't specify it anywhere. Its OSC camera. 

I had no problem with the filter in the past on other objects. 

Dan Brown avatar
Looks to me like lens flare. The blob on the right may be caused by the star Electra.
Dan
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