I'm building my own electronic focusers based on the MyFocuserPro2 open-source project. I've finally gotten it functioning on my AT60ED and got my first successful v-curve in N.I.N.A. last night! (*shakes angry fist at clouds*) By attaching directly to the 10:1 fine focus shaft on the focuser, I'm able to get about 8.5 steps in the critical focus zone, which I'm hoping is good enough for this scope. I could also microstep, if need be, but I'm running with full steps right now.
A couple things I noticed when I was trying to get it to focus made it easier to repeat getting a good curve:
- Move the focuser manually, watching looping exposures, and set it so it's just barely beyond the critical focus zone before starting the AF routine.
- I found it might be better to change the calculation method for finding best focus to "Trends and Parabolic".
But this is so new to me that I just don't have a good grasp on fundamentals or best practices, yet. So I have a few questions that I'm hoping more-experienced imagers might be able to help answer.
- Does anyone have any advice for me to have consistent success with the electronic focuser?
- Am I using too-coarse or too-fine of step increments according to my graph? (Increments were motor 10 steps.)
- How many step increments do you recommend I move outside of focus when I start the routine? (I was using 5, I believe.)
- Should I consider a different calculation method? (Trends and hyperbolic? Just hyperbolic? Just parabolic? Just trends?) Which tends to provide the best results?
- Without using temperature compensation, how frequently should I be refocusing? (I also have longer focal length scopes up to 1000mm, which I imagine are more-sensitive and require more-frequent focusing..?)
- Do you recommend taking more than one exposure per position?
- Anything else I should know?
Here's the graph from my first night of success:
My first automatically-focused test shot (with some wispy clouds...):
Edited by Noobulosity, 22 July 2021 - 12:21 PM.