New GM-8 – First Light

Aug 2009 – Finally, a night with stars and a chance to test out my new GM-8.

I recently bought a brand new Losmandy GM-8. I bought this mount to serve as a portable (almost grab-n-go) to take when I head up into the hills to do imaging. I found that my CGE is just too much mount for me to pack up and take remote, and my CG-5 is too finicky. I thought the GM-8 a good compromise.

On first receipt of the GM-8, I was impressed by the apparent quality of the mount, overall very nice fit and finish. However, the new equipment curse has kept the skies cloudy, and last night was the first opportunity to actually see how the mount performs.

I’ve had no previous experience with Losmandy mounts or the Gemini system so I was prepared to be befuddled and confused, but actually all went pretty well.

I set the mount up with an 80mm refractor and DSI-II camera to align and test guiding with. A polar scope came with the mount and it proved quite accurate. It must have had the mount very close to the pole because alignment was a breeze. After sync’ing to the first alignment star, every additional star landed near the center of the camera chip. I aligned to 6 stars then tried the Gemini polar correction routine which turned out to be very easy to do. The amount of correction needed was only about 8 arc-mins, which again suggests the polar scope was pretty much right on.

I tried guiding using PHD and it calibrated first try and seemed to guide pretty well. I then tried using the Gemini’s routine train PEC. Using the guide camera I captured, averaged, and smoothed, 4 PEC training runs. Then with PEC enabled, the guiding smoothed a little more. Looking at the data with PEAS showed it was guiding with the raw data (noise) at less than 3 arcsecs p-p and Avg PE less than +/- 0.2 arcsecs. For a light weight portable mount, I’m very satisfied with the out-of-the-box performance of this GM-8.

I’m a happy camper today,

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