I have used SGP for a while now and have never been able to get auto focusing to give usable results. I have a long focal length RC, 2000mm. It fails constantly, probably because SGP does not handle central obstructions and long FL scopes very well. I have gone thru so many options and many failed nights. SGP really needs an external focus software that does not require some special ONAG and cam or other expensive hardware other than the focuser you already have. Focus Max would be a good choice.
The only two things that are a bummer in SGP is the focus function and the fact that the interface is so bright. I can hold my nose on the interface but not the fucusing.
What focuser are you using? On my TOA130NS (2,7in focuser) Takahashi I had a RobotFocus installed and had a lot of problems trying to find the right setup in SGP. Best hfr was 1,10. Main problem was probably the small step number I had to use (around 6). I finally switch to a new focuser FeatherTouch 3,5in. With this new configuration I use 375 steps, 6sec, bin2 and I get hfr 0,76 with excellent focus every time. I also heard that collimation could be a problem when curve is not symmetric.
I have tried from over 1000 to 10 steps with many in between those numbers. I used the calculation to come up with the number that I used many times. Collimation is very good on this scope.
I am using the Sesto Senso focuser. When I manuallly focus it (using the software to manually focus) it gets very close to the return marks on my focus tube. Thing is, SGP auto focus goes right thru good HFR values, plots them and then ignores them and fails. The sesto is a strong little unit.
I have read thru the docs many times, looked at a lot of youtube vids. This is why I’m looking for something a lot more robust. I am not expecting an answer to this any time soon. Thank you for your reply though.
It really just depends on if those are acceptable values for auto focus…for instance my focuser step size is so fine I need to use 1500 for the step size. On many focusers using very high step sizes is getting to be the norm since you have geared drivers that are multiplying the steps.
If you want to post some AF logs or even the auto focus packs we can take a look.
I had teething issues at first as well. My focal length is 2563 with a HUGE central obstruction and the focuser is an Optec Gemini. A little Googling pointed me towards trying a MUCH larger step size. I am using 1800 for a step size now and getting great results.
I use a C14 at 2730mm focal length. SGP autofocus works fine for me so the problem is not your CO or the length, but probably one of settings, or mechanics. If conditions are a tad cloudy focus can be thrown off, but I’m having a lot of joy with the new autofocus routine. For the record one revolution of the focus knob translates to 4,000 steps on the motor. I use a step size of 120. No gearing involved and I focus directly on the primary.