I'm considering buying an auto focuser to use with the William Optics GT 81 refractor.
Is there a particular one that works best with Stellarmate?
I've lookaed at ZWO AEF and Pegasus FocusCube.
Any of these you recommend?
I think that is a very personal question. People like the stuff they have if it works well, even if they purchased it on a whim. I started out with a ZWO camera and by now have bought several and they all work great according to my highly biased opinion. I also bought the ZWO EAF and have been using it on several telescopes. As a matter of fact, I bought several because I am so happy with it.
But I never used a Pegasus FocusCube so I cannot comment on that.
Do both focusers fit on your telescope? If yes then I don't think it will matter very much which one you buy.
Wouter van Reeven
ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
1. Has someone else attached a particular auto-focuser to your telescope before, did they post instructions and results online about it. If they got good results then that's a really good sign.
2. Ensure the auto-focuser uses a stepper motor, as if you really want automatic focusing via one of the algorithms then this is a must, if it just uses a DC motor then the step size in one direction will typically not match the step size in the other direction (unless you're pointed at the horizon).
3. Are you going to be keeping the telescope on the mount all the time, or will you pack it in to a hard case, if packing away time after time, be sure that your hard case foam can accommodate the auto focuser still attached to the focuser.
5. Will you be doing visual, and wanting to manually focus with the auto-focuser still attached, many auto focusers don't support this, and require you to remove the auto focuser if you want to manually focus via the knob.
Looking at the specs for both, they are about equally matched (although the Pegasus says it can do 1/2 steps, so technically the resolution may be greater but not sure you could use it). I have an ASI EAF and really like it. It works very well with Ekos. I think you couldn't go wrong with either of these. Does red or blue match your gear better? The only hiccup I see with the EAF is that China was having trouble satisfying orders for brackets several months back (and since I bought, possibly the focuser's too). Might want to talk with someone at HighPoint or similar to see if you can get the focuser + bracket you want.
Hi. I use one ASI EAF at my APO, a Pegasus Focus Cube 2 at my SC and two Pegasus Focus Kit V2 with an DMFC at my Newtonians.
I changes to Pegasus, becaus (as far as I know) the EAF ha sonly 60000 Steps to travel which is for my SC a little bit too less so I got the Focus Cube for my SC.
After purchasing my first Newtonian I thought it would be cheaper to switch on the Focus Kit, which needs a DMFC additionally. This DMFC can be used for other Focus Kits. Now I own two of the Focus Kits. End of the year I will get my 12 Inch F5 Newtonian which will then gets his (my third) Focus Kit...
I'm satisfied with both Pegasus and ASI, but most of the time I work with the Pegasus.
David, I'm using the Pegasus FocusCube. It is of brilliant build quality and absolutely precise and reliable. I can only recommend it.
Installing it for the use with my Sigma135mm lens needed a bit of fiddling but it works very well now.