New SGPro 4.3 Feature: Automatic Focuser Positioning at Sequence Start

SGPro 4.3 is coming along nicely. Unfortunately the official release of 4.3 is wholly dependent on the stability of AutoFlats. This takes time… and so whilst waiting, I implemented a (not perfect, but better) version of the focuser’s initial position system. So, here is what SGPro (and higher) has:

There was an old option buried deep within the secondary focus control panel window that allowed you to enable the old initial positioning. This is gone now, and in its place, the new option now appears on the primary focus control panel tab:


In terms of old sequences and profiles, this new option will be enabled if you had the old absolute positioning option enabled.

How it works…

  • Sequence starts
  • SGPro attempts to find the last known (now recorded in sequence) focus position for the last sequence start.
  • If it finds one within 15 days AND within +/- 1.5 hours of the last starting time (3 hr range), use it as the current starting position
  • If starting filters are different, optionally apply focuser offset between the 2 filters
  • If none are found, default to the filter’s absolute position
  • If sequence has temperature compensation enabled, apply it
  • Run initial auto focus

Note: It likely won’t stay this way, but in order to use this now, you need to also have the “Auto Focus at sequence start option” enabled.

It may be possible to ease the time proximity requirements with use of temperature compensation, but I think that most temp comp applied over a large temperature delta is unlikely to succeed anyhow.

Open to ideas on tweaks here, but if they are too complex in nature will need to wait until “not 4.3” or we’ll never release. This version was allowed into 4.3 because it is not super-complex and is unlikely to hold up the release.

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Thanks Ken. I enabled the option and look forward to tomorrow to see how it performs.

In the “not 4.3” category, at one point you and/or Jared talked about keeping track of temperature/focus points so SGP could start very close to the correct focus position based on the current temperature. IIRC this feature was on a “to do” list and something was added to the log file to facilitate it.

Am I remembering incorrectly, or is that still the plan?

You’re remembering correctly. We added in some better focus position logging for some experimental work that is being done. We have some ideas for making auto focus better and faster and needed the ability to capture some additional metrics to prove out some assumptions. But that work is no where near completed or really even started.