Hi Fred,

That's very good news!

I have been thinking about this a little bit. The way it currently works is how you describe... flats will be taken at the last successful focus point for the selected filter.

I suppose technically, if its necessary to refocus every hour you could take a set of flats every hour. But I doubt anybody will be bothered to do that.

The other option is to extend Adaptive Focus to flats. Have you tried Adaptive Focus?. My idea would be that when the "Capture flats at the focus as lights" is checked and "Adaptive Focus" is also checked, the focuser moves to a temperature (and if configured altitude) adapted position, where the adjustment is based on the temperature difference between when the last successful AF run happened and when flats are being taken. It would use the Adaptive Focus parameters setup in Filter Settings and used on Lights to adapt the focus position between subframes.

I think this is doable, although its actually a bit harder than it sounds because the code is not structured to allow this without some refactoring.

My concern is that people (like me) will take flats indoors where the temperature is significantly different from the outside temperature at which Light frames were captured. In this case the simple linear relationship between focus point and, say, temperature that works overnight for a few degrees C temperature movement will be less valid for potentially much larger temperature differences. The counter argument would be that it might well be more accurate that not adapting at all!

I'll think about it some more but would welcome any thoughts / feedback.