autofocus question

[bottletopburly]

For those using an autofocus unit do you use it to actually  autofocus as intended  or do you still use the bahtinov mask and manually tweak from the pc ,and what program do you favour to use to control.

 

dave 

[Merlin66]

I use one with a reflective slit on the spectrograph- just adjust until we have a tight Spectral image.

This is on a C11 @ f10.

 

[PhotoGav]

I have a Lakeside motor focus system for all three of my OTAs and run autofocus from SGP. It has been almost perfect, so long as focus is roughly right to start with, except for my current target, M2 with my Edge 8”. I haven’t used a Bahtinov mask since changing to the Lakeside system!

[Dr_Ju_ju]

I use "home-built" non branded systems, & all works a treat using SGP\APT etc.....

[Joel Shepherd]

You want to have your focus close before you switch over to autofocus. The autofocus routines generally assume that is the starting point and then test the focus across a range of positions around that point to fine tune it. While focus position can vary somewhat with temperature, I find it works well enough to spend a night or two getting your initial focus (with a Bhatinov mask, or manually adjusting the focuser and using a frame-and-focus utility), autofocusing the luminance or clear filter, recording that position and then using that as your starting position for autofocusing going forward. It will be close enough that 1-3 runs of the autofocus utility will reliably dial you in on subsequent nights and with your other filters.

[bottletopburly]

27 minutes ago, Joel Shepherd said:

You want to have your focus close before you switch over to autofocus. The autofocus routines generally assume that is the starting point and then test the focus across a range of positions around that point to fine tune it. While focus position can vary somewhat with temperature, I find it works well enough to spend a night or two getting your initial focus (with a Bhatinov mask, or manually adjusting the focuser and using a frame-and-focus utility), autofocusing the luminance or clear filter, recording that position and then using that as your starting position for autofocusing going forward. It will be close enough that 1-3 runs of the autofocus utility will reliably dial you in on subsequent nights and with your other filters.

Thanks for the tips Joel