Looking at auto focus during an imaging session I noticed that some of my later subs (6 to 8 hours after the sequence started) were out of focus. Not just one – but a few in a cluster right at the end of the night. When I looked closer at what was happening I found SGP doing the opposite to what I expected……maybe my understanding of the ‘new’ focus regime is incorrect. I’ll provide a link to the full SGP log but a couple of examples of what has me baffled:-
Time 02:01:28 the log shows new method autofocus @ 286, old @273
At 02:02:09 SGP sent the focuser to 273. As I was watching the AF routine & graph low point, I decided to step in and put the focuser manually at 286. The subsequent image was fine.
I changed the Min Star size from 6 to 8.
Again at 03:35:00 the new method shows 362 and the old shows 345. It sent the focuser to 345. Again I stepped in and set it manually to 360. The sub focus was OK (could have been a little better – but was not way off)
So – why is there a new method of focus calc in the system and then SGP uses the old? I have not gone back through the log – these were ones I was watching on the screen and was very aware of where the graph was showing the focus point. I was so surprised to see the focuser being instructed to go to a very different point.
On my next run I will watch this again during the earlier part of the sequence. I did not see any problems in the earlier subs last night – but cannot say one way or the other what instructions were being sent by SGP in relation to the graph low point. You will note in the log probably that focusing (and filter changes) slowed down considerably late in the session – as mentioned in another thread (re Atik EFW2). So I am unsure if comms are getting slow for some reason……but RAM usage was only at about 33% and SGP did not appear to be using significantly more than at other times.
Any ideas – have I misread what was actually happening?
Re slow filter change & focusing: I have no hard evidence - but think this is ongoing for a while now…OK early in the sequence and slower later. I don’t think it is cable. Might it be HUB related? Feels more like a RAM problem - but there is no evidence of that.