You want to aim for about 33-50% saturation of your camera's sensor for flats:
saturation=well capacity/gain.
On my STL-11000M, it has 50,000 well capacity and 0.8 electron ADU gain:
50,000/0.8=62,500 ADU saturation point.
So, you'd aim for 20,625 to 31,250 ADU.
Substitute values for your 8300-sensor.
I worked out an optimal value, which was around the 42% mark for some reason. Either way, I've put my minimum and maximum ADU values in CCD Commander and it takes care of the rest.
H