[mldee (Mike)]

Just got an ASI EAF with the ZWO-designed mounting bracket for the C8. Got it all together and then realised that the ZWO firmware only allows 60 thousand "steps", which translates to about 10 turns of the C8 focus shaft. Maybe 65 thou if you change the default setting. Found some entries on Cloudy Nights saying this was real, and a headache, as end to end focus on the C8 is about 47 turns or such. This means the EAF will only adjust over about 1/4 of the range needed

Go search CN for more detailed descriptions of this and other users' complaints and suggested solutions, etc.

Apparently ZWO says to preset the SCT manually to approx best focus before tightening down the coupler and then use the EAF as a "focus fine tuner". Depending on whether you're Hyperstar, .63 reducer, or full bore, the basic focus position will first need to be set. Bit of a PITA, but hopefully will still allow full autofocus function in NINA etc for each mode of operation. You can also reset the software counter to zero and then go through another iteration of 60K steps, then rinse ands repeat, plus there's a "reverse" option. This is what I did this morning. Slow but works.

I did get mine into good focus this morning on some local cross-valley scenery and will try autofocus with NINA next week when I have some time.

I'm a bit disappointed in the lack of mention of this limitation by vendors and in the couple of Youtube videos that describe EAF + SCT install, so just be prepared for a bit of head scratching while setting up the focus software. Google is your friend.