Ripple pattern on QHY 268M flats

[tooth_dr]

Any ideas what could be the issue here?  Cant see any frosting on the sensor, and it's in at least two filters I've tried Ha Sii.  The bottom left corner it is most obvious.

 

[Davey-T]

Hi Adam, not seen that before, have you tried a different light source to eliminate that ?

Dave

[tooth_dr]

1 minute ago, Davey-T said:

Hi Adam, not seen that before, have you tried a different light source to eliminate that ?

Dave

Cheers Dave.  I didnt try a different light source but I did rotate the light 90 degrees on the OTA and the pattern didnt change, so I wonder is it a mark on the sensor glass, maybe a water/condensation mark?  I'll pull the camera off the scope tomorrow and take a look at it.