Autofocusing becomes unfocus with different filter

Hi, being using SGP for sometime, but this weekend when the autofocusing started the focusing was well out. I aborted the sequence and did a focusing run using the blue filter ( i have the correct steps calculated using the blue filter) with the telescope parked, and the ‘V’ curve was prefect, giving me a 74200 focusing point with 1.2 HFR, but when i restarted the sequence and target the object perfectly the autofocusing was out again, after the third try it stopped.

I checked on the Ha filter parameters to see if there was a fixed autofocuing point attached to it, but there was non. I disconnected the autofocusing, and fixed the position to the 74200 thinking that it would keep this position when I restarted the sequence and after completing a first frame of the object looking at 400 zoom there were donuts stars.

Any help will be appreciated, not sure if its a software issue or a mechanical of the internal focuser (I am using a Takahashi 250 -active focus internal system).



It’s unclear if you’re using the blue filter to focus for the HA or if this is just on the blue filter. If you’re using the blue filter and Filter Offsets then it sounds like your offsets are potentially off and you may need to redo them. Can you post a log where this happened?


Thanks Jared, I meant that in oder to find the critical focus zone , thus the steps to achieve a proper ‘v’ shape i used the blue filter to make the calculation. On the log will do this this week when I go to my observatory.

Thanks for your help