AstroPhotography Tonight

CGEM Astrophotography- The Next Phase

Posted on 06. Jan, 2010 by Ray Shore in Astrophotography News

The next phase for me with my Celestron CGEM is to begin using it for astrophotography. I have done some webcam imaging of Jupiter with marginal results (not due to the CGEM, but other factors such as seeing conditions), but much of my interest is in imaging deep space objects such as nebula, star clusters, and galaxies. To start with, I will perform DSLR astrophotography with the Orion ED80. To get started though, I had to make an investment in some new gear! 

Below is a photo of my astrophotography setup for the CGEM. There are four types of adapters involved. Most of them are ADM adapters for mounting the ED80 to the CGEM and the autoguider scope to the ED80 (piggybacked). The others came with the autoguider (guide scope rings and mounting bar). The DSLR is a Canon XSi. More detail on my astrophotography setup below. 

CGEM Astrophotography Setup- Click to Enlarge

CGEM Adapters

I decided to mount the ED80 directly to the CGEM saddle plate. I had the ADM dovetail rings and adapter set already (previously used to piggyback the ED80 to the LX200 SCT) so it was a matter of purchasing the DMM7 from ADM. This allows me to mount the ED80 to the CGEM saddle plate. 

Autoguiding

Another important component is a suitable autoguiding system. I’ve been hearing a lot about the 
Orion Awesome Autoguider Packageso I made the purchase. It’s composed of a ShortTube 80mm refractor and StarShoot Autoguiding camera (for a very reasonable price I might add). 

I needed a way to mount the autoguider to my ED80 dovetail rings so ADM set me up with two V-Series clamps that mount to each ring. This will allow the autoguider’s mounting bar to attach to the top of the ED80 dovetail rings. Thus, the Awesome Autoguider will be piggybacked to the ED80. It will be a nice light optical system for my CGEM. 

Astrophotography Camera for the CGEM

I decided to upgrade from my Canon 300D and into the Canon 450D (XSi). I have been seeing some excellent astro-images with this camera (combined with the CGEM in many cases) so I’m going to give it a try! It is a 12.2 Megapixel CMOS sensor DSLR. A nice feature is the live preview mode which may help with focusing. 

Bahtinov Focusing Mask

I’m also hearing a lot about Bahtinov focusing masks. Some imagers are making these masks themselves but a professionally made one is very reasonable. In fact, it was only $14.95 for the Bahtinov mask for my ED80 at telescopes.com. These masks allow fast and easy critical focus. It’s simply a matter of adjusting focus until a symmetrical diffraction spike pattern is obtained. 

The Wait

Now I’m just waiting for my equipment to arrive and for some suitable weather! I haven’t been able to use my CGEM too much lately because of the bad weather. Hopefully we will get a break soon so I can get more experience with this awesome mount and start producing astro-images. I will continue to post my progress here on AstroPhotography Tonight so please keep checking back for updates!

Tags: astro-imaging, astrophotography, Astrophotography Tutorials, CGEM, CGEM review