I am getting residual calibration artifacts in my light frames coming through from flats, due to the fact that each flat set for a filter and rotator position angle is taken to a target illumination ADU and the exposure time changes from one flat to the next to try to keep that target value. This leads to a set of flats with different exposure times and it is difficult to take that many flat darks to match to each flat frame. What I want is a set of flat frames that starts at target illumination ADU and then keeps exposure time constant for the rest of that set. I can then take a dark file that matches that exact exposure time.

What I need is strategy where Autoflat.vbs searches for the starting exposure time as it does now, but when the exposure is found that reaches target ADU, the exposure is kept constant for that set of flats. This means that the illumination will get lower for each flat at dusk or greater at dawn. But each flat will be calibrated exactly the right exposure dark and stacking will handle the illumination differences.

In the AutoFlatConfig.txt I know I have the ADUAcceleration_AM and ADUAcceleration_PM factors. If I set these to 1, I believe that the script will do constant exposure for a set of flats, but will the script properly search search for the right starting exposure time for a set?

If no, does this mean I need to edit the AutoFlat.vbs script to get the result I want?

Any insight you have for the path to solve this issue would be helpful.