Speed up autofocus procedure

[Former user]

During my few and unfortunately due to the wheather so far short tests, N.I.N.A. always starts the complete automatic focus procedure. So will it be perhaps a good idea to do the following: when a sequence starts and N.I.N.A. will do the first automatic focus procedure, the HFR-values are stored. Then when during the capture sequence the next automatic focus procedure should start (after x frames, after x minutes etc.), N.I.N.A. will measure the HFR-values and if they match the values from the previous automatic focus sequence or the values are within certain defined thresholds (difference of x percent), there will be no focus procedure and N.I.N.A. will continue the capture sequence (until the next focus procedure should start). This could perhaps speed things a little bit up. But I am not sure if this is a really good idea or if so has been already implemented in perhaps a similar or better way.

[Oaklandish]

This is a good idea. If NINA selects the same star/stars for the measurement than it should be fine. This is an option that is included in EKOS/Kstars as well. In EKOS you enable a refocus if HFR is > (enter number of) pixels

[Yannick Dutertre]

A solution addressing that problem has been added to NINA 1.9, the ability to focus once the image HFR becomes worse than original HFR by X%

[Nils Harnischmacher]

Thank you for implementing my proposal, Yannick! I saw already that you have done that. But I was only (due to non-NINA related problems) able to test it for a short time. During my test, the HFR value was stable and therefore (correctly) AF didn’t jumped in. So it seems (as always) to work great! I will further test it and give more feedback. But due to my (hardware, guiding and clouds) problems, that will probably take some time. Thanks again! Nils