Re: APPM requirements


Speaking of “requirements”…

What’s the thought on using APPM with a non-permanent setup?

Fwiw, I’m using the mach2 now with an st8300m + fs128 at about 1040mm focal length and am “visually” seeing decent round stars with 5 minute unguided exposures.   

I’ve only had the mount for a couple weeks, but I also used the 130GT at 614mm with (iirc) 20 minute exposures unguided.

Yes, objects do not land in the center of the chip on a goto , but it is usually close enough such that I can plate solve , sync , then goto again (for proper framing).

I’m guessing APPM might help with longer exposures , and also with objects low on horizon affected by atmospheric distortion… the latter would be nice to correct for.  At this point I image objects when they are fairly high on the sky.

What would be the guidelines for a “portable” setup ?  
a) create model at the site but it could be reused for the same location?
 b) or.. it is necessary to re-create model if the mount is moved.. ie polar alignment is re-done?

I’ve just wondered about the practicality for a non-permanent setup, and the conditions where APPM is needed for unguided imaging… eg the focal length where APPM becomes effective over just the encoders on a polar aligned mount..  Or is the benefit simply repeatable pointing accuracy?


On Mar 23, 2021, at 12:39 PM, Dean Jacobsen <deanjacobsen@...> wrote:

Ray's APCC/APPM on-line manual is a great place to start.

There is a specific section for APPM that I used to get everything set up.
Dean Jacobsen
Image Gallery -
Astrobin Image Gallery - 
Amateur Radio Call Sign - W6DBJ

Join to automatically receive all group messages.