Autofocus Exposure Time

Where is the exposure length for automatic focusing specified? I am assuming it is under Control Panel > Use auto focus > set (opens autofocus options interface) > under Options > Exposure times…

Is this where SGP looks for when executing automatic focusing?


You need to set this in an equipment profile (in the Focus tab -> Use Auto focus->Set), one of your equipment profiles will be set as ‘Default’ (you choose which one if there is more than one profile), the ‘Default’ profile will be loaded when SGP starts up. All your control panel settings will be set based on what this profile has in it, the control panel is then independent from then on. If you want to experiment with auto focus exposure lengths change the setting in the ‘Frame and Focus’ module or the control panel focus tab itself until you find an exposure length that works for your setup. Then, update that figure in your ‘Equipment Profile(s)’ and save it. When SGP starts up again that figure will be auto loaded from then on.



So you are saying autofocus exposure time will be set per filter and it will be saved in the default equipment profile unless I want to have multiple profiles in which case I save custom profiles, right?

Pretty much yes - Each Equipment Profile is unique to a particular Equipment Setup…Not too sure how it works with filters though as I only do OSC, I think focusing will generally only be done with your LUM filter but someone else experienced in all the filters & things can chime in here on that subject.

I do know that certain filters like Ha ,iiO etc will require different/longer exposure times to equal, for example, what a 6 sec exposure will give you with an OSC when it comes to focusing.

I have 6 sec set for my auto focus frames and that seems to be perfect for my OSC camera, maybe a Ha frame requires 25 secs to get a reliable focus frame for auto focusing I really am not 100% sure.

I assume the box on the lower right of your image is where you would put these unique exposure times for each filter and if one of those filters is called/loaded in a running sequence and auto focus is fired up then it will take the exposure time you have set there to expose by.

Please can someone chime in here and make sure Farzad is sorted here


Thanks for the input.

My filters are parfoclal, and I have tested them when I first got into monochrome imaging. I have been focusing with L.

Do you know if a minimum HFR is recommended for autofocuing to have a chance?

Depends on seeing conditions at your location on the night, it can vary wildly night to night, I have had auto focus finish on 0.7* before now but the same settings on another night can end up at 1.7 or even more.

I takes time to get to know your kit and conditions at your location, I dont find that the resulting HFR makes a huge amount of difference except for a very slight blurring when it is higher…

Carry on regardless Farzad because I have lost huge amounts of data due to silly mistakes and had what I feel are great successes over time. Astrophotography is an incredibly hard pass time but time and mistakes solved will get you great results in the end.

This pic of M81 / M82 is probably the best I have got so far:

The fits header does not say what the HFR was and it’s probably pretty crap compared to what some guy’s produce on here but hey…I’m happy with it and it’s took me 3-4 years to get this far.


I don’t really know how accurate HFR is any way. If we had a chance of living somewhere dark with clear sky for a while we could probably figure out how it ticks. But given the shortage of opportunity trial and error is the best thing we can do.

Nice image, by the way.