Please add this feature, it is an absolute must have to achieve focus on any SCT! I have a celestron C11 and these are designed in a way that there is a bit of mirror adjustment that happens when you change direction of the focuser. What happens is during your auto focus routine you find the curve correctly, no issues, but when it’s time to do the fine focusing to get the best point you go in clockwise direction, stop, take first pic to set a reference… but then you turn focuser counter-clockwise which results in image issues because of a direction change, and now it’s blurry and it shows worse focus, yet your fine focus routine uses that blurry focus point as the SHARPEST point in the routine. It is wrong and now my image in not it’s sharpest possible.
You need to add “overshoot” as part of the autofocus routine. That means, that after you get the curve and switch to fine-focus, lets say your routine identifies the first fine-focus point should be 5000 on the encoder. You need to go to 5500 (this is the overshoot), then reverse direction back by 500 so that you are at 5000 but accounted for the mirror direction issue, now start fine-focus steps of 5000,4990, 4980, until you get the sharpest star.
right now on SCTs, auto-focus FAILS 100% of the time, the routine says it’s in focus, but it’s NOT!
This should be a simple setting under the EAF, right where you have backlash you need to add an “overshoot” and let us put in a number…. For example 100 might be good… but Celestron recommends 500 for their SCTs as the overshoot…. So anytime the focus knob has to change rotational direction it applies the overshoot correction.
