regarding OP points 2 & 3:

Point 2: While I concur that the method of measuring HFR can be a step in a better direction, HFR readings can be very suspect to momentary bad seeing variability. A slightly more rigorous approach would be better. IMO, it was a mistake to allow users to set a step size directly in the GUI. This info should have been automatically calculated from known parameters of the optical system and a user estimate of best seeing and acceptable focus tolerance. See this reference for details:
www.goldastro.com/goldfocus/ncfz.php
Folks who take the time to read the above will know the size of their gear's CFZ. A 1/3 CFZ stepsize would give ensure the right focus is always obtained (for well functioning focusers). The most difficult aspect of the above is that the Ekos step size must be known in motor counts, not microns. To find the correct step size in motor counts, a user must drive the focus motor through some measured focuser travel (or know the thread pitch of the internal focuser's drawtube and motor counts per rev). Many refractors have a scale right on the focuser to make this easier, so the #counts per mm (for instance) can easily be found. In the end, the # of motor counts per micron yields a correct mathematical answer for step size. IMO, the GUI should have been better thought out and is at the root of much of the confusion.

On point 3: I've been using a developed temperature based focus compensation (also with altitude residuals) in my own Ekos branch for many months now (search temperature compensation for postings). I have reduced my autofocus runs to a minimum. I don't waste precious observing time on focusing any more. I offered the code to anyone who wanted it and suggested it could help the community. I made clear from the start that I wasn't a GUI developer, and I developed the feature with a config file. Some suggested a GUI was desirable (I didn't disagree, but it isn't necessary strictly speaking). Unfortunately, no volunteer was found to develop the GUI to replace the config file (used for controls and function(s) definition). So, the community wide effort was abandoned for lack of interest. Some folks actually prefer the simplicity of repetitive focusing. For my f/2.2 rig, this was too much of a waste of time to bear. To each their own! Cheers, Doug

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