Strange focus setting behaviour


I have accurate focus positions set in the equipment profile and at various times I have enabled / disabled the focus shift on filter change as I compare different approaches.

My understanding is that when the filter changes, the focuser moves by the difference between filter focus positions (relative movement). I use a microtouch focuser with actual focus stepper values around 35,000. (I always have my focus module powered down to the 30,000 mark for consistency across my various telescope combinations to a fixed 40mm extension, so if anything gets out of sync, I can reproduce the exact focus extension.)

I’m not so clear on what should happen with the sequence start and especially compared with a manual filter or focus selection.
I sometimes A/F before I start a sequence to set up the guider and I have had an instance when the sequence started, SGP tried to move the focuser to 30,000-35,000- hitting the endstop. I’m sure this is not supposed to happen by design.

This is just a heads-up. I suspect this has something to do with the manual luminance filter selection is being treated differently to an initial sequence filter selection. I need to be able to reproduce the conditions that cause this issue and with logs etc. before making a more formal response to the team.

Right now, my question is, has anyone else seen something similar? I’m using 2.4 beta(2) but I have no data to say it is specific to this version.


I have tracked it down - it is one of those silly little things where customer finger trouble and software combine to cause unexpected behavior. It occurs in Beta 3 too. I checked it out with the ASCOM simulators.

I have a set of filter focus positions set to 1001,1002,1003 etc for R,G,B,Clear etc. I have ‘auto adjust focus per filter’ enabled.

I accidentally hit ‘set’ on the filter dialog, when the filter selection dialog is blank (the default when you power up SGP) but the filter indicator is showing Red. The focuser moved by -1001. In effect it behaved as if there was a filter position named ‘blank’ with a focus position of 0. Of course, the ‘blank’ filter disappears for all time as soon as you hit the drop down arrow on the selector.

It would seem then that when the focus wheel is powered up and the filter position is shown by the colored indicator and label, the drop down dialog should also update too to a legal filter position.
Does that make sense?