The forecast appears much more favorable in my area than it has been for several days and I'm getting ready to image my second narrowband target, the Heart Nebula.
I am using an ASI1600MM with the ZWO 31 mm unmounted filter set, run through ASIAIR Pro. The narrowband filters are listed as parfocal on the ZWO website.
I imagine best practice is to focus between filter changes? I have 6.5-7 hours of time off my battery, so was planning on 3 x 6 hours nights for image acquisition. I'd prefer to average image rotation, seeing conditions, etc Ha, OIII, and SII each of those nights. But I won't be babysitting the scope to refocus. ASIAIR does not yet have autofocus for filter changes.
So after all my rambling, should I really just do a single filter a night or will it not be that big an issue with focus changes between filter changes?