After getting the necessary equipment together and waiting for a clear night, I finally got to try out astrophotography with my CGEM! I spent a lot of time yesterday getting my observatory prepared with some last minute touches. Soon after sundown, I was performing a polar alignment in preparation for imaging M42, the Orion Nebula. This would be my first target with the CGEM, Canon XSi, ED80, and autoguider. Shown here is the CGEM all ready to image:
I knew it was not going to be the best night for deep space astrophotography because of the full moon. But I wanted to at least try out the new equipment. M42 is a bright target so I hoped I could get decent results.
Canon XSi Setup
This was the first time that I got to use the new Canon XSi for astrophotography. I sold my Canon Digital Rebel (300D) which provided a lot of good photos with previous telescope setups. One thing I really like about the XSi is the EOS Utility that allows for remote imaging with the bulb setting. And, it uses the USB cable that comes with the camera so no need to purchase (or make) a special one. There is an automatic routine that lets you set the number of exposures, intervals, and exposure time and follows through automatically.
Focusing used to be a bit difficult in the past but now I have a Bahtinov Focusing Mask. This thing makes focusing incredibly easy and fast! I bought an inexpensive one here at telescopes.com (thanks to a tip from Jeff Turner over at DaltonSkyGazer). I just laid the mask over the end of the ED80 and did a quick exposure with the XSi to see the diffraction pattern. A couple tweaks of the ED80 focusing knob and it was perfect. I hoped that it would show up in live preview, but for some reason it did not. I’ll have to figure out how to use live preview for focusing with the mask next time.
Once I got the XSi ready to go (focusing, centering of M42, etc.) I got the autoguider going.
Autoguiding with the CGEM
I have to admit, this is the first time that I have ever done any guiding! I used to do a precise drift alignment with my LX200 and keep my exposure times to a minimum. I had to sort through a lot of frames to find ones that were suitable to use for stacking.
I recently purchased the Orion Awesome Autoguider Refractor Telescope Package. This is becoming a popular solution for guiding due to its low-cost as a complete system. It comes with a ShortTube 80mm refractor, Starshoot Autoguiding Camera, dovetail mounting bar, and rings.
Using this system with the CGEM was rather easy. One cord plugs into the autoguiding port on the CGEM and the other cable plugs into the USB port on the computer. It runs off of a software program called PHD Guiding. There’s just a few simple steps to go through before it starts to guide.
Overall, the performance of the autoguider on the CGEM was excellent. Once it locked onto the guidestar, I didn’t have to worry about M42 drifting. I was able to use all of the frames that I shot through the XSi. In fact, each frame looked identical. All of the stars were in the exact location from frame to frame and all were round. This was very exciting! I hope to do a write-up of the autoguider soon. It is so simple to use and makes a big difference in the outcome.
More information: Orion Awesome Autoguider Refractor Telescope Package.
The only part of the autoguiding process that could have been better, was the calibration time. This took awhile! It took about 15-20 minutes for the calibration to complete. I’m wondering if it has something to do with my remote setup though. I’m running everything in my observatory on Cat. 5e cabling (underground) and using USB over Cat5e adapters. Unfortunately, they are USB 1.1 adapters instead of faster USB 2.0. I need to upgrade to the faster adapters eventually.
It took me a few hours to get everything going before I could actually begin imaging. I was dealing with new equipment, some technical snags, and at one point in the night, complete cloud cover! Furthermore, there was a full moon and M42 was about to set. So I only had time for a few shots with the XSi. I managed to get 12 light frames at 60 seconds each and 12 dark frames for calibration. I was determined to have something to show for all my work through the day and night. It was almost 3:00 am when I started shutting things down. Here is the resulting image (click to enlarge):
Things should go smoother as I get more experience with this equipment. Next time I hope to take longer exposures and more of them. Look for more information as everything unfolds. So far the CGEM appears to be a nice platform for astrophotography. I am seeing some excellent photos coming from this telescope from the astro-imaging community. I hope to show the same results soon!
Update: Image from 2-2-2010!
Took more exposures this time. Here’s the details:
16 x 80 seconds at ISO 1600
10 x 60 seconds at ISO 400
I tried a free stacking program called DeepSkyStacker for this image of M42. I thought it was SUPER easy to use and it worked very well! You can download it here. Enjoy!
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