I've created a Focus Introduction YouTube

All feedback welcome!

I plan to create some more videos on topics like:
- Adaptive Focus
- Autofocusing vs Offsets
- Using different Star Measures, e.g. FWHM, Fourier, etc
- How to optimise star detection for focus using SEP

Let me know if you'd like anything else to be covered.

Great contribution! I can’t wait to watch it. I’m anticipating it will help me out a bunch.

I don’t know if this is even possible but it would be nice to see how well or even if one of the focus methods could be used for lunar, solar or even planetary imaging or observing. I know some people are also interested in how the focus methods work with dslrs using dslr lenses.

Thank you,
Eli

Spectacular John!

I wish we could also have more similar videos from other devs explaining their contributions. It is beneficial to understand better.

Great job for the video and the code of course

Great job John !
Thank you very much !

I watched it with great interest and learned quite a few things from it...

Perfect timing as I've just finished reading the focus section of the Kstars Handbook docs.kde.org/trunk5/en/kstars/kstars/kstars.pdf#focus
Been struggling with the auto focus lately.

Great video, it does cover a lot. Thanks for taking the time in making it. Much appreciated.

Great contribution, John. One area that would help, is understanding how to setup the focuser when its attached on different sides of the focus tube.

There's a "Reverse Motion" Indi property on the Indi Focuser Tab that you can set. You want the inward most position to be 0 and the position to increase as you move outward.

Extremely helpful and a superb presentation, many many thanks!

I am struggling a lot at the moment with a new RASA 11" and its 4 micron CFZ on my rig.
With your detailed explanations I can eliminate a lot of guesswork and optimize my current approach.

One thing I currently do not understand is, if I change a filter, I assumed that the focusing process would automatically use the calculated offset to get in the new optimal focus zone.
But this does not seem to be the case for me. And this is a big problem for my rig when I do not start autofocus at nearly optimal focus.

Looking forward to upcoming videos!

Thanks very much for your kind words! I'm going to cover this in my next video on Adaptive Focus, but since you asked....

There is a feature within Adaptive Focus, called Adapt Start Pos that will start an AutoFocus run from the last successful run for that filter. Here's an example, I just ran Autofocus on the Lum filter. It solved at 36850 as can be seen in the Filter Settings popup...


So Autofocusing on Green, if Adapt Start Pos is checked, it was start the Autofocus from the last solve on Green which is 36685. Here I just hit Autofocus and then stopped it...


You can see the log message (highlighted). Note that Adapt Start Pos will do more and adjust for temperature and altitude if you set this up in Filter Settings. If you don't want to adapt for temperature or altitude then just set the values in Filter Settings to 0.

So the concept of Adapt Start Pos is to start the Autofocus run as close to optimum focus as possible. As mentioned above its possible to use this feature independently on the rest of the Adaptive Focus functionality.

HTH

Hi John, I discovered the reverse bit the hard way when I got my focuser, so what I was trying to say was that it would be good to cover this in the video (if not done already).

Hi John, awesome! Thats exactly what I was looking for. Stood away from adaptive so far and haven't noticed this yet.
I will try that tonight

Many thanks, Norman