Anthony123495
It is the characteristic of the sensor, and can be calibrated.
Please try these links.
https://www.facebook.com/groups/zwoasiusers/permalink/1405257593166618?form=MY01SV&OCID=MY01SV
https://www.facebook.com/groups/zwoasiusers/permalink/1399824943709883
Some other customers have the same situation, It is the characteristic of the sensor, and we attached a calibrate method from Simon for your reference, you can try it.
Things I see regularly are:
Not using flat dark calibration process - do not use bias on this camera!
the best results are by using darks that match flats well - use same gain - length and temperatures
using 28K as ADU value
ensuring the light source has well balanced channels. - RGB channels must be well aligned else one channel will under / over expose - sadly usually red!
do not use less than 3s exposures on 294MC pro - less than this can lead to inconsistent values in ADU
create a master from the short darks and calibrate the flats by using the master and calibrate only - do not optimise
create a master flat with the calibrated flats
create a master dark that matches the lights use same gain - length and temperatures
calibrate the lights - again do not use optimise only calibrate
using these steps I have not found an issue with my L-ext or Lenh / ZWO duo etc
most problems I have seen are not following these or stretching flats and worrying about the pattern - yes you will see the pattern sometimes stronger on some setups - not all setups seem to have the same response
I hope these help but this article did more harm than good as I see it reposted all the time
294mm show similar patterns but again can also be managed by the above process
