The would explain why I often see the same HFR values for stars when the focuser moved far enough that they HFR values should have been very different.
I get this error at the start of the any focus method.  The Esatto claims to move the focuser a bit, but the corresponding star values didn't change.  And later on, I get a different error where the star values are very different at the exact same focus position.  Many times after the focus routine stops and gives me a reading… I then hit the manual capture button and get a totally different reading.  But subsequent exposures show the HFR is stable.

The other focus issue I always see is that in the LINEAR mode, after EKOS has calculated a perfect focus position, EKOS then goes on to select a different position instead.  I verified that indeed the calculated position was always better than the final one EKOS selected at the end of the session. I have to go back in and manually move the focuser back to the one calculated correctly during the focus routine, but oddly NOT selected in the end. 

Read More...