Re: 3-4" RA wiggling while PHD2 guiding with EXOS2-GT PMC-eight #EXOS2 #astrophotography

Jerry Hubbell - Explore Scientific VP Engineering

Hi Walter,

I am just starting to look at your guide log, but I did notice that your guide camera (an Orion Starshoot Autoguider) with a 5.8 um pixel coupled with your very short focal length guide scope (162 mm) makes you image scale very large at 6.6 arc-sec/pixel. This is a big problem if you are trying to auto guide to < 2-3 arc-seconds and is very difficult to get any better performance. This will especially the case if you seeing is poor. 

I will spend some more time looking at your guide log to see if I see anything else.
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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