Web Cam Eyepiece
How to take a web camera and adapt it as an eyepiece to take images through a telescope or microscope.
I started with a HyperCam Mobile from Aiptek for £30. Any web camera should be fine. In the past I've found black and white CCD cameras to produce good quality low-light images.
It should also be possible to do the same thing with a video camera circuit such as those from Maplin (around £40 for grey and £80 for colour) if you want to get TV video output rather than PC connectivity
Inside the casing is a little circuit with a lens unit that unscrews to reveal the CMOS chip. This camera contains the near-IR filter within the lens assembly so it cannot be used separately in the eyepiece version.
The two inter-locking base elements (green bits here) from some twist connectors made suitable spacers for the circuit board to fit into a Maplin project case.
One half was glued to the case, the other half to the circuit board so that the board would slot comfortably in place but still be easily removed if necessary.
Here is the camera re-housed in a case that makes it easier to get access to the internals and play around with lens adaptors. As you can see from the picture the lens mounting around the CMOS sensor was not removed. This enables the original lens to be screwed in to turn the device back temporarily into a webcam, although there's no reason why it can't be removed to get the sensor closer to front of the housing.
Finally, a hole was drilled in the cover and glued on an adaptor that allows the unit to be attached the to the micoscope. The tube was the hardest piece to find - I ended up buying a second hand eye-piece without the optics for a fiver.
The final item. To be used on a microscope lack of near IR filter has to be addressed.