Full Spectrum Canon 550D (T2i)

Astro-Tech 12" Richey-Chretien Telescope

Orion HDX110 GoTo Mount

First light test of both scope and mount

Cherry Springs Dark Sky Park - April 27, 2014

by Gary Honis

I received delivery of a new Orion HDX110 equatorial GoTo mount on April 23. I took it to Cherry Springs Dark Sky Park to set it up for the first time. It was also my first time using a 12" Astro-Tech RC telescope. We collimated the telescope the day before. For lifting the heavy mount (55 lbs.) onto the pier and the telescope (50 lbs.) onto the mount, I used a small hydraulic lift table that I took with me. The tripod/pier weighs 65 lbs. and I used a large plastic container with wheels to move it to where I set up. Images through the 12" RC were taken with a Full Spectrum Modified Canon 550D (T2i).

The EQMOD ASCOM driver was used to drive the HDX110 mount directly via a USB2EQ5 Interface Cable.

Equipment used:

Although I was set up with the SteadyStar unit in the optical train, for this first light image, I only used it as an off-axis guider and rotator. I did not use the SteadyStar software for adaptive optics guiding, but instead used PHD Guiding software. I later tested the SteadyStar software with adaptive optics and it worked well. One problem I had was a severe vignetting from the unit's pick off prism. I had it set in a very low position while I had been previously using it with my 20" Alt-Az Starmaster. To avoid the vignetting from the pick off prism, I had to make the sky background much darker than I normally would.

The Orion HDX110 mount was polar aligned by only using the polar align scope.

For this image, the night sky began very transparent but with poor seeing. Transparency degraded somewhat over the course of the night. There were mild breezes, but they did not affect imaging. The temperatures dropped to below freezing overnight with frost forming on our equipment. In the morning I took a lot of dark frames automatically and found that I only had five that were good. The remaining flats were brightened by what I think was light entering the scope through the cooling fans at the back of the optical tube. I also took flats in the morning but they did not completely remove the vignetting from the OAG prism, and I will try again with the prism in a higher position. It was great being able to use the Full Spectrum modified T2i without an IR blocking filter for increased luminosity and detail.

M101 Spiral Galaxy - RGB only:

20 six-minute exposures at ISO 1600 captured with AT12RC at prime were combined using DeepSkyStacker and reduced in size for display (1200X800). Five dark frames and 20 flats were used for calibration.


On May 6, 2014, from my driveway with moderate light pollution, I used an Astronomik 12nm H-Alpha clip filter to image M101 in H-Alpha. The First Quarter Moon was in the sky. I took 12 twelve-minute ISO 1600 exposures using PHD guiding. 11 darks and 49 flats were used in DeepSky Stacker for calibration. The H-Alpha was added to the RGB image in Photoshop using the "lighten" selection in layers. Because of differences in how the images were framed, I did not have h-alpha data for the leftmost side of the image.

M101 Spiral Galaxy with H-Alpha added:

DSLR Modification Service: I am selling and converting Canon 450D, 500D, 550D, 600D, 1000D & 1100D DSLR cameras for astro imaging. CLICK HERE for details.

Images taken at Cherry Springs Dark Sky Park in May 2013 CLICK HERE

Images taken at the Fall Star Party at Chiefland, Florida in November 2012 CLICK HERE.

Images taken at Cherry Springs Dark Sky Park in August 2012 CLICK HERE

Images taken at Cherry Springs Dark Sky Park in July 2012 CLICK HERE

Images taken at Cherry Springs Dark Sky Park in June 2012 CLICK HERE

Detailed instructions for modifying a Canon 450D, 1000D, 1100D, 500D, 550D, 600D & 650D CLICK HERE

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Astro images with the modified 450D: CLICK HERE

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