Using the PMC-Eight to track the Eclipse

Devin Gingrich

Hi everyone,

Just wondering if we could start a thread with advice/tips for getting an EQ aligned for daytime use and using the PMC-Eight to track?

Any tips/tricks you have for getting a good daytime alignment?

Anything special needed in the app for solar tracking?



The method I use is to first level the mount as precisely as you can with a independent level, not the ones mounted in the mount. Then use a compass, compensating for magnetic declination, to align the azimuth to North. If you are careful, you can get within 1 degree of the NCP. Make sure your mount's RA and DEC are set according to any markings to make sure they are centered. The G11 has bubble levels for this, and the EXOS2 has little arrow marks to line up on each axis. Once you have done that, position your mount using the hand controller very close to the meridian so that the counterweight bar is horizontal. You can use the coordinate input screen on the ExploreStars application for this by entering 180 degrees in the Azimuth coordinate. Enter 90 degrees - Latitude in the Altitude coordinate and the mount will slew the telescope to a vertical position. Once your mount stops moving, then you can place a level on top of your telescope tube (assuming it provides a flat across the opening) and adjust the Altitude adjustment on the mount to make it level. At this point your mount should be aligned within 1 degree or better if you were careful.

I have used this method for several years when setting up my system during the day.

W. Christopher Moses

In terms of solar use and solar tracking, I tried it once using TheSkyX and it worked fine.  I was already polar aligned from the night before, so I just slewed to the sun and refocused.
    Obviously, I wasn't guiding, but the sun stayed nicely centered for the 2-3 hours I watched it.
    I would imagine CdC or other programs would also work.
    I'm headed down to North Carolina to watch it, you?

Devin Gingrich

I’m in the DC area and am setting up several scopes for a viewing event with ~150 kids. I’m hopeful ES will get the EXOS2 with PMC-Eight back in stock soon enough so I can include it (carrying my Comet Hunter) in the lineup. :-)


Thanks for the setup details Jerry. I tried it out and it worked pretty well. I still had some drift so I worked on fine tuning but never got it entirely stable. I'll try again this weekend to see if I can get azimuth dialed in to stop the motion. It was drifting south so I think I was too far east. Overall with a 952mm scope and 1.6x Canon DSLR I was able to track reasonably well...Probably needed to adjust roughly every 5min to keep the solar disk entirely in frame.

One interesting note - I tried using a different bubble level instead of those on the mount as you suggested in you setup description. They do give different results. I'll try using this other level the next night I go out and see if my night tracking improves.



Hi Tim, I know the instructions were a bit terse, but I am glad you were able to get it to work for you. The more you practice it, the better you will get at it.