Jump to content


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


EQM-35 PPEC training

Astrophotography Mount Software
  • Please log in to reply
1 reply to this topic

#1 ple


    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 01 Oct 2020
  • Loc: San Diego, CA

Posted 21 January 2022 - 04:45 PM

I recently (October 2021) purchased an EQM-35 Pro with SynScan V5 as my first "serious" mount for astrophotography. I'm getting fairly good results with 30-second subs, but if I try to go any longer than that to 60- and 120-second subs, I lose a large number (anywhere between a third and three-quarters) to periodic error. I've confirmed with Skywatcher customer support that my equipment supports permanent periodic error correction.


The information in the SynScan instructions that shipped with the mount is quite thin, so I'd be interested in hearing from anyone who has successfully trained PPEC on an EQM-35. I'd rather not make the jump to autoguiding yet for cost reasons. It seems to me that I ought to be able to use something like PHD2 in conjunction with the camera I normally use for astrophotography (a Nikon D5300) to train PPEC, but if I have the wrong conceptual understanding of how this process works, I'm hoping this forum can correct me.


One caveat is that I'm using a Mac laptop. For mount control I've been using CloudMakers AstroTelescope 4.2 quite successfully, although I could probably switch to KStars/Ekos easily enough if that's what's necessary to get PPEC working.



Edited by ple, 21 January 2022 - 05:57 PM.

#2 Dwight J

Dwight J


  • *****
  • Posts: 4,091
  • Joined: 14 May 2009
  • Loc: Lethbridge, Alberta, Canada

Posted 22 January 2022 - 04:03 AM

I don;t think that PhD2 will detect your Nikon.  Your best bet if you don't have a guide camera is to use an illuminated reticle eyepiece and using the direction buttons on the handcontroller to manually guide on a reasonable bright star around the meridian and the ecliptic by using the RA direction buttons to speed up or slow down the tracking to keep the star centered in the crosshairs.  Selecting PEC in the menu hit the start button and guide until the hand box beeps indicating that it is complete.  The annoying part is that this is not retained by the mount and will have to be redone every power cycle.   The idea is that the corrections you enter are recorded and then replayed back and the mount tracks so errors are corrected without further guiding.  Getting better polar alignment goes a long way to extending unguided exposure time as well.  I have an EQ3 SynScan mount and can attest to how doing this does improve tracking and could extend your exposure time.  Getting guiding going would be no less hassle than this procedure.  Once you start guiding you never go back.

  • ple likes this

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Recent Topics

Also tagged with one or more of these keywords: Astrophotography, Mount, Software

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics