(Potential) SGP integration with Focuslock - Questions

I’m reading a bit about the Optec Lacerta and SGP’s potential integration with Focuslock, I am now intensely interested in Focuslock and the Optec Lacerta. With a longer focal length scope on the way, continuous focus would be ideal since the tolerances of long focal length imaging are more stringent.

As it relates to SGP I have some questions:

  1. I’m thinking that autofocus will still be necessary at times. Will the integration of SGP/Focuslock be such that autofocus can still be triggered?

2.Perhaps it would be best to pause Focuslock when doing filter changes or other movements so as not to throw off the focuslock star shape and potentially chase focus (I’m thinking of a nightmare scenario where my focus motor runs wild)?

More questions as I think of them…but I also realize this is early early early in the thinking/development stage. Focuslock just sounds really ideal and would love to see this integrated in SGP.

Yes. We would pause FocusLock and perform the normal AF then restart FocusLock. Out of curiosity, why do you think this would be necessary? Non-parfocal filters?

That is a reasonable idea.

Yes. I actually use a mix of filter brands so the focus points are somewhat different. I’m not sure how filter offsets would work with Focuslock either. For example if I focus with my Optolong LUM filter and then move to my Astrodon Ha filter the focuser needs to move as much as 500 steps because of the difference in optical glass refraction. With Focuslock I get the feeling that it is super critical that the guide camera and imaging camera are parfocal(?) with each other. In my case with different filter brands that could cause a problem. Even now, when I am imaging with the Astrodon Ha filter, the guide star in PHD2 is noticeably softer than when guiding while imaging with the LUM filter because of this difference of glass refraction focus points.

After AF we’ll likely need to tell FocusLock that the new “star shape” is in focus. I believe they also have the ability to connect to the filterwheel and set offsets to the lock position based on the filter selected.


Cool. I’ve asked these questions with Optec as well. The more I think about this the more I think this has huge advantages.

Hi there.

I notice on Optec’s website under FocusLock that it lists what you need to use it. One of the choices is SGP.

So I came here to search for how to get them to work together and sorting by latest post I found this thread which seems to indicate it is a wish-list item that you will work on some day.

Or did you already get it incorporated? I was looking at focus setup under equipment profile and I do not see anything that says FocusLock which is what I would expect.

Or is there another way to set it up?



While we intend to support tighter integration with focus lock, there is nothing to stop you from using it now. You will just want to ensure that AF in SGPro is disabled.

Thank you Ken.

My confusion was due to SGP being listed as supported software on Optec’s website. This made me believe that there was some sort of existing integration that I was not aware of.

System Requirements:

Microsoft .NET Framework 4.5 (available from Microsoft)
ASCOM Platform 6.1 or higher (available from the ASCOM website)
For guide camera control, you may use any of these programs:

Maxim D/L version 5 or 6 (Diffraction Limited),
TheSky X (Software Bisque),
PHD2 Guiding v2.5.0dev2 or later (Open PHD2 Guiding)
NOTE: If using PHD2 Guide, you will need the Development Snapshot Build available here,
Sequence Generator Pro (Main Sequence Software),
or any ASCOM guiding program using the Optec ASCOM Server