EKOS team,
I am having trouble focusing on an automated basis for my Rasa 8. The CFZ is extremely small about one step. I seem to be hunting all over the place to focus manually because auto focus does not cut it.

First question, EKOS does not seem to calculate the hfr correctly when the stars are donuts. Is this true??
Starting with donuts how do I walk this focus in (which parameters?)
Just trying to get a starting point.... Bruce

Hi Bruce,

I'm currently working on a project to improve focusing in the presence of donuts as you are correct is saying that Ekos struggles to calculate the HFR correctly and this can lead to Autofocus failing.

Probably the best way is if you can post some screenshots of the 3 Options panels (settings, process and mechanics) and I'll make sure the parameters are set optimally. Also, if you are using SEP can you post a screenshot of the SEP parameters page. There are a couple of parameter tweaks here that will hopefully make a difference to your setup but lets make sure that all the parameters are set sensibly.

GentlemenHere are the screens for the focuser, INDI, then process, settings then mechanics. Thanks for any help on this issue…. Bruce Screen shots attached,,,,,

Hi Bruce,

I'd suggest the following changes:
- SEP Profile from 3-SmallSizedStars to 1-FocusDefault
We can make some changes to this - more later
- Algorithm from Polynomial to Linear 1 Pass
- Curve fir from Quadratic to Hyperbola
- Use Weights On
- Refine Curve Fit On

You have a very small step size = 1. I'm not familiar with your equipment so this may be OK - don't know at this stage but I've never seen anyone set this value so low before.

You have both Backlash (=50) and AF Overscan (=100) set. Whilst this may be OK, it causes some issues with some focusers and you probably don't need both. Personally I would set Backlash=0 and AF Overscan above what your real backlash is. So if real backlash = 75, for example, set AF Overscan = 100. Given your step size = 1 having AF Overscan =100 seems huge but again I don't know your equipment so can't really judge.

Now back to SEP parameters... I would set Min Cont from its default which is probably 0.005, to 1.0. And set max ellipse = 1.5. These changes should help with donuts. Its upto you if you change the profile or create a new one and edit that. I would personally create a new one so you can go back to the defaults easily if needs be.

If you are able it would be good to post the results of Autofocus (the v-curve). I should be able to suggest further parameter tweaks then.

Hope this helps.

Clear skies.

Thanks John, I will test on next clear night. Maybe a while.
Step size is something I am still experimenting with, F2 the CFZ is tiny. I will increase but not by much... I will let you know.

John,
Success, although I also changed the step size to 500. Thanks for your help!

Hi Bruce,

Looks good!

One of the things I'm trying to improve is defaulting of step size. When you get a chance could you please post a screenshot of your CFZ screen please (launched by pressing the CFZ button on Focus).