Hi Sonny, I sent you a PM. We can deal with any questions via PM from here. CS Doug

Can I somehow specify the maximal number of steps during focusing? I am using Linear algorythm and yesterday something goes wrong. The focuser was focusing more thant13 steps during first set of steps (before changing to half step size). The V-curve was no more a V-curve as the HFR after 6th step turns lower. It seems that I have accidentally changed one setting in my DeepSkyDad AF3 focuser driver: step size from 1/8 to 1/2

I always get the same issue - in that EKOS calculates a good curve after 6 or 7 steps, but for some reason it continues to do a dozen or more additional steps that are never needed.  
In this attached screen shot you can see that by step 6 there is a good curve,  But it continues on for 10 more steps in the same direction needlessly.  How do I fix this?  

 

  

This the same problem I have observed. Thank you for the screenshot Peter

I think "Out step multiple" set to 2 is too few: you have only two shots on the right-hand side of the V. Have you tried with a value of 3 or 4?
My two cents.

My setting for "Out step multiple" is 3. But I don't understand why there is 10+ iterations for first right-left cycle? Is it possible to made it more "inteligent" and once there is an obvious curve, the algorithm will do second cycle?
Based on screenshot from Peter, the second cycle could start right after 8th iteration has been done.

That's how Polynomial algorithm behaves. I suppose Linear algorithm needs more data points.

Thanks Jasem, I will then try to switch the algorithm to Polynomial

The linear algorithm was developed to overcome certain issues that people experience. More likely for when there is a certain amount of backlash and perhaps when you're not using a stepper motor. It takes longer to achieve focus, but I think people get better results.

If your AF has a stepper motor, and the backlash is minimal, or able to be compensated for, then I would normally use the Polynomial algorithm (which I use now, and usually get good results).

I have DeepSkyDad AF3 focuser with NEMA stepper motor. I will try to test both algorithms tomorrow

Hi All,

I changed over to running EKOS around a year ago and in that time I have not been able to run the focus module successfully with my 8” RC, standard crayford focuser and iOptron EF. I have reached the point where I have good steps in and out, use linear algorithm and get a ‘sort of’ V-curve. All setting seem to be about right for my setup and visually Autofocus seems to drive nicely out-of and back through focus.

My problem is that the module fails with ‘fail to detect a star’ when the image shows an annulus - this is even stepping outside a nominal focus by orders of 10s of steps. The annulus is bright and tracked in the green reticule, but EKOS seems to not track the outer diameter and maybe is attempting to measure part of the annulus rather than the whole.

I’m any case, it will only focus around 1 in 20 or more attempts and even then tweaking does better.

After browsing many discussions on focusing and probably missing the important one, I’m stumped! Can anyone point me in the right direction to track the outer diameter of an annulus for successful focusing?

Many thanks

Mark

You have to adjust the Sep star settings to allow it to recognize larger star sizes. But even then, you shouldn’t have out if focus star sizes larger than 2 or 3 times the HFR size of an in focus star. Do if your in focus size is 1.5 then your largest out if focus sizes should be no more than 3 or 4”. I get great fox’s results thus way. I never let it focus so far out as to show a star as a donut.