One of the first things you realize when doing astronomical observing is that the objects you are looking at don’t look like the photographs. You rarely see color, mostly just faint fuzzies. But by using long exposure photographs you can bring out more details then you could hope to see with even the best telescope. While the faint fuzzies are impressive, I found that I wanted to see more detail. So I began my hunt for a camera.
Which camera to chose?
There are two basic types of cameras used for astrophotography, DSLR and CCD. Each type of camera has it’s own benefits and drawbacks, but I chose the DSLR for a few reasons. First, I liked the fact that I could use a DSLR for daytime photography. I’ve always been frustrated with point and shoots, and this became my opportunity to step up. At the time, I also liked the fact that I didn’t have to bring my laptop out into the field with the DSLR. CCD’s require a dedicated laptop computer. As it turned out, I prefer using my DSLR in conjunction with my laptop, anyways. It makes focusing, framing and reviewing a lot easier. It also means that I can review my photo’s while shooting without disturbing the current shot. As well, DSLR’s are much more affordable then CCD’s.
The DSLR I chose was the Canon XS. At the time, it was Canon’s entry level DSLR and it came with features that help during an astrophotography session. Live view, for example, allows you to see and zoom in on whats in the viewfinder from the camera’s LCD or from your computer. It also allows you to set up a series of timed exposures(while hooked up to a computer), which previously required a separate timer hooked up to the camera. All in all, the Canon XS makes a very good imaging camera for astronomy.
Next, I had to attach it to the scope. I purchased a Celestron T-Ring and T-adapter. A T-Ring is specific to the camera model as it threads onto a DSLR just as the lens would. The T-adapter threads into the T-Ring as well as the telescope. Once all of the pieces are attached, the camera is hooked up to the scope. From here, I had to find a way to focus. Fortunately for me, there was a partial moon out, and I was able to use the moon for focus. At this point, I had already brought my laptop computer outside and hooked it up to the scope. Now, rather then looking at the moon through the eyepiece of the scope, I just sat down at my camping chair and observed the moon on my computer screen. I could also zoom in on any point in the image just by clicking.
So I snapped my first astroimage. Then I adjusted the exposure and took another image. My results are above.
Moon photography is the easiest type of astrophotography. It is a big bright target, and doesn’t require much image processing. A single short exposure photograph can be amazing. This differs from planets, which tend to be smaller and require multiple short exposures, and stacking or combining of exposures to add detail. Deep sky photography is the most advanced and requires precise tracking of the target and long exposure photographs. In future articles, I’ll be concentrating on my introduction to deep sky photography.
Continued in Part 3…