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Thanks for that comparison Rob. Looks like the FSQ106ED and RH200 are very close in resolution and PSF. This would make data combination from both quite easy.
I always dither when collecting data. The native resolution is of course 3.09' per pixel for the PL16803 camera RH200 combination. The RH200 has better resolution than the sampling of the PL16803. By upsizing all frames by a factor of X1.5 before stacking to now give a potential resolution 2.06' per pixel this inherent resolution can be recovered. More frames gives better resolution enhancement.
This is mathematically sound according to The Sampling Theorem.
If your frames are dithered you should try upsizing x1.5 and then stacking. I am sure you will see an improvement in resolution especially with the dim small stars.
The Atlas Focuser is about as good as it gets for focussing. I can see a difference in the Bahtinov diffraction pattern with only 100 steps (8.5 micron). The critical focus zone of the RH200 is about or less than 10 micron.
Even though the RH200 is very temperature stable I heat the RH200 and most of the image train back to the filter wheel with eight dew straps 24/7. These dew straps are controlled by a PID PWM (Proportional Integral Differential Pulse Width Modulated) temperature controller that keeps the set temperature constant +- 0.1C. In summer I set this temperature to 20.0C and in winter 14.0C. This way focus does not change overnight with ambient temperature changes. In fact it does not change over many nights unless something is disturbed.
This heating of optic works better with a sealed optic, as at constant temperature there are no convection air currents. This should work very well with your FSQ. I used to do the same with my Canon 300mm lens as it had terrible focus variation with temperature.
Hope all this rambling helps.
Bert
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