I still haven’t managed to get my planetary imaging webcam setup working yet. But in preparation for the Kelling Heath Star Party this weekend I have managed to procure myself a Canon EOS 1000D digital SLR camera. I saved over 50% on the list price by getting a refurbished/returned model and to be honest it’s probably not going to have a good life out in the cold attached to a telescope so I didn’t want to spend a fortune on a new camera, especially after getting a new mount, telescope, coma reducer (a field flattener to make stars look pinpoint sharp), light pollution filter, rings to connect it all together, and so on 😉
To say I am impressed with the quality of the Canon 1000D is an understatement. After coming from a line of premium compact travel zoom cameras, this Canon digital SLR with it’s large, sensitive sensor and quality optics is capable of capturing some amazing images. Considering that I’ve never used an SLR camera before, I’m quite happy with the results of this evening’s test photographs.
The reason why astronomers like digital SLR cameras and specialist CCD cameras is that by using these cameras in prime focus (screwed directly onto the telescope tube), the telescope optics become the lens and the sensitive sensor of the camera is able to pick up and accumulate the photons of light much better than our eyes can.
Our eyes have evolved over millions of years and one of the problems inherent in our line of evolution is that our optical wiring runs in front of our retina (the sensor part of our eyes). It’s a shame the architecture of our eyes sucks so much; squid and octopus don’t have the same “design fault” in their eyes that ours do! We also have an array of rods and cones which respond to photons of light and send the corresponding signals to the brain. This light sensitive patch of cells in our eyes is incredibly fragile and does not respond well to low levels of light such as the few dribs and drabs of photons that have travelled through the cold of space for millions of years before hitting them. And for the objects you can see visually through a telescope, you’re unlikely to see much colour (other than the colour of some individual stars) and not likely to resolve much detail of the deeper space objects such as distant galaxies and nebulae.
This is where a camera comes in. A camera is able to absorb all the light from an extended period of time and form a combined picture. Many of these pictures stacked together can form an image. And it is such images that are my goal, since I can then share the view from the eyepiece with my family and friends and you 🙂
Hopefully I’ll have something interesting to report in time!