Based on a whole host of recommendations on various websites I managed to track down a secondhand Philips SPC900 webcam on Amazon. The drivers and software I downloaded from the Philips website.
The power of this particular type of webcam is that it is possible to take a video of an object and then stack the individual frames on top of each other to create a much better image. Obviously one doesn't want to be stacking thousands of frames by hand so it's best to use a specialised software package. I downloaded a package called Registax that is widely recommended.
For my first webcam session, the final pieces of the jigsaw were a couple of Barlow lenses. Planetary observing calls for high magnification and narrow field of view so focal extenders are vital. I already had a 2x Barlow and added a 5x Barlow that I ordered from Telescope House.
So I was set-up and ready to go, just waiting for my chance which eventually came on February 9th 2010. Unfortunately this was a moonless night so my options were limited - the easiest target wasn't around, Jupiter was setting a little too early and not visible from my garden, Saturn was rising a little too late. This pretty much left me with Mars which isn't the easiest of first targets. Still you've got to start somewhere!
To sum-up what is about to follow, as an observing session it was a disaster. I did almost everything wrong and didn't produce any images of any quality at all. However I did learn an enormous amount about webcam astrophotography.
The first problem was actually getting the target into the field of view of the webcam. My finderscope clearly wasn't aligned as well as I thought it was - it's one thing to view the target through the telescope but something completely different to get it into the much smaller field of view of the webcam. Add to this the extra clutter of having extra equipment and a laptop to contend with and at times it was rather frustrating.
Once the target was in the field of view there was then the problem of focussing it. Even without a Barlow lens the target would move across the whole field of view in about 15 seconds. This isn't much time to get good focus on a laptop screen. Also the webcam picks up ultraviolet and infrared wavelengths not perceptible to the human eye which adds a haze to the image making it harder to focus.
The other major problem was getting the right webcam settings. I had played around with the settings during the day but this hadn't fully prepared me for picking the appropriate gain, frame rate and shutter speed during an observing session.
Despite these problems I took a number of videos so that I had something to practice with in Registax. Using registax for the first time was a pleasant experience. Although the number of options and controls was slightly intimidating at first, I soon realised that the basics go a long way. I will do a seperate post on my Registax experience in the near future.
For completeness I will include the final processed image from one of my videos. As an image in itself it is rubbish but as a demonstration that one shouldn't expect great things from a debut webcam session it is perfect!
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