Help with rings

[steviemac500]

I have to admit it's been a while since I've done any LRGB shots - mainly NB. I'm shooting a mosaic of M31 and stupidly shot whilst the moon was up and took in some quite bad LP into my shots. I'm using my G2 -8300 with 1.25" internal filters. I know there is some vignetting but normally my flats have taken care of this and I have had no trouble with any of my NB shots. However, the rings in the corner of this is typical of all 6 panels and I'm not confident I know what it is. Do you think the moon LP has exacerbate the vignetting on these and will reduce as the moon goes away?

I've also noticed that the dust motes haven't been taken care of either and the flats match these up perfectly so I'm sure they are ok - again no issues with the NB stuff???

Thanks.

Edit - I should add that these are simply autostretched to highlight the issues.

[steviemac500]

Anyone?

[ollypenrice]

Could you expand on what you mean by the flats matching perfectly?

It might be a good thing to post a stretched flat, a stretched image with flats and a stretched image without flats.

You do have an unusual artefact, for sure. Could the flats be over-correcting? (Try using a master bias as a dark for flats.)

Personally I would never attempt a broadband mosaic with the moon in attendance. It can be hard enough as it is...

Olly

[steviemac500]

20 hours ago, ollypenrice said:

Could you expand on what you mean by the flats matching perfectly?

It might be a good thing to post a stretched flat, a stretched image with flats and a stretched image without flats.

You do have an unusual artefact, for sure. Could the flats be over-correcting? (Try using a master bias as a dark for flats.)

Personally I would never attempt a broadband mosaic with the moon in attendance. It can be hard enough as it is.

it seems to be moon LP. The shots from last night from the second panel of with the 38% moon are much better.