Astrophotography for a beginner by a beginner
As mentioned in a previous post, I took some simple astrophotography pictures with my cell phone camera. A meteor, the moon and the eclipse were relatively easy targets. I had been bitten by the astro bug.
I decided it was time to live out my childhood dream and get a real telescope. I had always dreamed of a Celestron 8″ Schmidt-Cassegrain. But when I started to investigate astrophotography, I found out that an altitude-azimuth mount was not the best for tracking long exposures. I needed something called a GEM, or German Equatorial Mount with Goto functionality. This would allow for really long exposures of Deep Space Objects (DSOs) and hopefully I could get some awesome photos.
Still looking for an 8″ scope, I started to learn about the differences between Refractors, Reflectors, and Schmidt-Cassegrains. What had better characteristics for capturing the best photos of deep space objects? I came to the (temporary) conclusion that I wanted an Orion 8297 8-Inch f/3.9 Newtonian Astrograph Reflector, then I thought at only $200 more I would go for the 10″ version. After watching many YouTube videos and reading lots of forum posts, I found out the tripod and mount would be 3 to 4 times the price of the scope to accommodate the weight of the scope, auto guider, finder scope and other necessary equipment.
Hmmm, I could afford it, and thought why not? Just to be clear for a beginner, it took me a while to figure out, most mount manufacturers rate the weight capacities for the equipment only. The rating you see does NOT include the counterweights. And to further the confusion, the general recommendation is to only load up to about 50% capacity to get the best possible tracking and the sharpest images and pinpoint shaped stars.
I have mechanical ability, a photography background and an understanding of how the earth spins, I should be able to handle this “not recommended for beginners” sized scope, mount and other equipment. Reading, watching, and more understanding only caused me to doubt myself. Is this a smart decision? While trying to understand if I wanted to make this leap, I found out you could actually take pictures of DSO with a DSLR and a zoom lens. What? I need to give that a try!
Fortunately, I figured out I could mount my Canon xTi (400D) on my 35 year old tripod, and from inside my sunroom, open the door and point at the constellation Orion and try for a shot of the Orion Nebula. Easy to find.
Through trial and error, I started to figure out shutter times but had star trails. Then I read about the rule of 500 (or 600 or 400), and determined that at 200mm, with the crop sensor in the Canon xTi (effectively changing 200mm into 320mm) , I could only take exposures of about 1.6 seconds. 500 divided by 320 equals 1.6 seconds. This would not be long enough to get a meaningful photo.
More research was needed for what I thought would be a fun little experiment. Then I stumbled upon the iOptron SkyTracker, this neat little mount allows you to manually locate and point to Polaris (if in the Northern Hemisphere) then it will track the sky. Now I am intrigued! Further research uncovered the best option for me was probably the more recent version called the iOptron SkyGuider Pro.
In my next post I will cover my beginner experiences with the iOptron SkyGuider Pro.