First time flats

[WireD64]

Can anyone help? First time creating flat frames and this was my result. Used an ipad on white screen and ADU of 25000, 100 frames (I know that's over kill but had the time) which kept histogram around 30-50% and then was calibrated with Masterbias and Masterdark and Integrated in PixInsight. I was expecting to see a regular vignette pattern but does this seem like a correct flat? Shown is the linear and stretched version.

[david_taurus83]

What filter was this? Looks similar to the flats I got with my Oiii filter last time. How long were the exposures?

[Demonperformer]

The proof of the pudding ... What does the result of your image look like when processed with the flats versus without?

 

[WireD64]

6 hours ago, david_taurus83 said:

What filter was this? Looks similar to the flats I got with my Oiii filter last time. How long were the exposures?

This was with a Ha filter, somewhere around 2 seconds.