Re: Orion Nebula M42 at the MSRO #G11 #astrophotography #TDM

Jerry Hubbell - Explore Scientific VP Engineering

On Tue, Nov 12, 2019 at 09:18 AM, <wcblack1020@...> wrote:
Was this with or without guiding?
Hi Bill,

Thanks for your kind words about my image.

We don't auto-guide at the MSRO, we use the Telescope Drive Master (TDM) drive correction system which is a high-resolution (0.125 arc-seconds/count) incremental encoder on the RA axis that sends corrections to the auto-guider port on the G11 PMC-Eight 5 times per second. The tracking error is around 0.3 arc-seconds RMS. I have been using the TDM for about 9 years now, I was Explore Scientific's first customer for the system in 2010. Before I was hired by ES in 2013, I did some work on the system for them, and  created some software to record data from the system that is available from our website. Here is a paper I wrote about the performance of the system.

The best thing about the TDM is that you can turn it on and forget it, no messing with an auto-guiding system which in my opinion is a pain in the ass. I found out early on when doing astrophotography that my time is worth more than the amount of money paid for the TDM. I am considered the expert on the system other than the guys in Hungary who developed it.

There is a big, long thread on CloudyNIghts from 2011. It was a pretty long and comprehensive discussion. I don't know if all the links in the messages work anymore.

Thanks for the question.
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at
1010 S. 48th Street
Springdale, AR 72762

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home

Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

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