Thursday, 30 April 2009

Starting to guide

My next adventure in astronomy is to start guiding, so that I can improve my photographs and really nail some good images.
I began the usual trawl of looking on the tinterweb for what was available to use to guide my scope and give me the stability in my images.

The choices for guiding are clear it would seem, you either sit in the CCD or webcam camp, now there is no questioning the brilliance of CCD (Charge Coupled Device) technology, producing high quality imaging and is a superb tool for guiding, with guiding CCD's able to plug directly into the guidescope port on your mount even, and guide the scope direct.

But CCD comes at a hefty price tag, with even a cheaper end guide camera coming in at around £150 without software. I simply cannot run to this at the moment, but hey, everyone has a webcam!

I have a Logitech Quickcam S7500, which works fine on my Macbook Pro, this coupled with the superb Keiths Astro Imager and I was set, the software recognised the webcam instantly and I was able to easily take images and use Keiths Image Stacker to produce an image of my office, Keiths Astro Imager also guides, so I was really pleased.

The last mountain to climb was a big one it seemed, as the world of astronomy is very rightly focussed on the rarer than hens teeth Phillips SPC900 and Phillips Toucam webcams, and therefore converters and extensions to couple your webcam to a 1" 1/4" are largely focussed around the afore mentioned excellent cameras.

So what to do? well it may be a little known fact but an old 35mm film case will slip very nicely over the end of an eyepiece, well my eyepieces anyway, if you take of the rubber eyecup you can easily pop the film canister on the end and it will stay put very well, excellent! Now how to attach the webcam to the canister. This is even less basic than the other end on the eyepiece. Cut the end off the canister and fix it to the webcam with the lens centered. On the Logitech the canister slips onto the front really well and even lips over the lens housing with a rather satisfying little click, a smear of silicone around the outside to hold in place and I was done.

This is obviously not as robust as the bought and purpose made adapters but I don't really care, it was easy and it works.

Results to follow, as well as images of the modded cam.

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