Autofocus with OSC and Different Filters - Forums

Topic starter

Frequent contributor

Mar 9, 2025

I never used an AEF before so I'm out of my confront zone, so to speak. So here is my problem: I'd need to use NINA autofocus capabilities (either the embedded one or Hocus Focus plug-in) but with different filters with different optical thicknesses and presumably different focus curves. Problem is that I use a filter drawer and manually switch from one to another as subject and opportunity command. Can those curves be saved and used in the standard sequencer or I need the advanced one, if at all feasible? What are my options, if any?

Thanks in advance for your help in this matter,

Andrea

jmdl101

Mar 9, 2025

I use an electronic filter wheel and just autofocus when I change filters, takes about 2 minutes. Nina has a filter offset calculator plug in also that you can use to set offsets for each filter if you want to try that out. In theory you could change the filter, chnage the filter in Nina, and then it would automatically move the focuser the correct amount for that filter.

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Noah Tingey

Mar 10, 2025

What @jmdl101 says is true. Set up your filters in NINA as if you had a filter wheel (treating "no filter" as one of the filters, assuming you do that sometimes), but then connect NINA to the "manual filter wheel" dropdown option in the equipment page. This will work as if you have a filter wheel, but it will pause the sequence and prompt you every time it wishes to change a filter.

If you're doing more than one filter per night, it might be worth setting up filter offsets. Takes about 30-60 minutes with a full set of SHOLRGB, but the upside is that you don't have to re-focus with each new filter. Just focus once on one filter (or with no filter) and NINA remembers how much it needs to adjust your focus based on the offset.

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