HI Yves,

I can't help you right now, but I'm almost sure to be in the same situation soon. I have a new set of LRGB filters I will be installing today or tomorrow, and I will then be going through the process of finding focus offsets, and then collecting new flats. I'm using an H-alpha filter in the mix, too, which based on your experience I might expect to fail. I have FMx5 as well, set up for muiltistar focusing. It will be interesting to see what happens.

FocusOffsets() does not use the usual AutoFocus() routine in AcquireSupport (which is wired to support FMx5 multistar focusing). Instead, it does its own FIndBrightStar and then calls the straight-up, original asynchronous focusing in FocusMax which should work the same in FMx4 and FMx5. The one, first image is the pointing exposure. Was there no message of any kind in the log following taking the pointing image?

Did you make all the necessary changes to the filter names, positions and min/max magnitudes?

In any case, I'll report back when I've run FocusOffsets for my new filters.