Repairing webcam telescope guide camera
Category: Astronomy Equipment
Posted by: Tom How
Repair job today at the Curdridge observatory. Webcams are popular in astronomy. They take great pictures of the Moon and the planets. With some fiddly soldering you can actually modify them to take longer exposures, e.g. 10 or 20 seconds.
This makes them useful "starter" cameras for people just starting out in astrophotography. Their popularity as imaging devices has waned a bit in recent years due to the advent of inexpensive DSLRs and CCD cameras, however, they are still useful as a guide camera.
My telescope is guided using an Off Axis Guider (OAG) unit I made. This type of OAG requires a guide camera with the sensor mounted at the front of the a 1.25 inch barrel. Not compatible with a webcam you might think... Several years ago I made a small camera case that fulfilled this requirement and mounted the webcam circuit board and CCD sensor inside it. At the same time the standard colour sensor was replaced with a black and white ICX098 sensor which makes the camera three times more sensitive. A few firmware re-writes and you've got a pretty competent little guide camera.
After years of faithful service, it stopped working the other day. The basic webcam function was ok, but the modified long exposure system didn't work. This is usually caused by a wire becomming disconnected inside the camera. The long exposure modification involves cutting the tracks on the webcam circuit board and soldering on some extra wires - soldering things on a 0.1mm scale often results in fragile connections.
However, two evenings spent messing about with the circuit and it still didn't work. Lots of blue language. Without the guide-camera the new telescope mount is an expensive garden decoration. Useless. Today myself and Pete completely dismantled and rebuilt the camera using a new webcam board (I have a lot of spares) and after far too many hours I got it working again.
Products like the QHY5 camera are available for less than £200 these days, so using modified webcams for guiding telescopes is not such a money saving trick as it used to be, but still gives you the DIY satisfaction.
This makes them useful "starter" cameras for people just starting out in astrophotography. Their popularity as imaging devices has waned a bit in recent years due to the advent of inexpensive DSLRs and CCD cameras, however, they are still useful as a guide camera.
My telescope is guided using an Off Axis Guider (OAG) unit I made. This type of OAG requires a guide camera with the sensor mounted at the front of the a 1.25 inch barrel. Not compatible with a webcam you might think... Several years ago I made a small camera case that fulfilled this requirement and mounted the webcam circuit board and CCD sensor inside it. At the same time the standard colour sensor was replaced with a black and white ICX098 sensor which makes the camera three times more sensitive. A few firmware re-writes and you've got a pretty competent little guide camera.
After years of faithful service, it stopped working the other day. The basic webcam function was ok, but the modified long exposure system didn't work. This is usually caused by a wire becomming disconnected inside the camera. The long exposure modification involves cutting the tracks on the webcam circuit board and soldering on some extra wires - soldering things on a 0.1mm scale often results in fragile connections.
However, two evenings spent messing about with the circuit and it still didn't work. Lots of blue language. Without the guide-camera the new telescope mount is an expensive garden decoration. Useless. Today myself and Pete completely dismantled and rebuilt the camera using a new webcam board (I have a lot of spares) and after far too many hours I got it working again.
Products like the QHY5 camera are available for less than £200 these days, so using modified webcams for guiding telescopes is not such a money saving trick as it used to be, but still gives you the DIY satisfaction.
simon smith wrote:
http://www.morgancomputers....
Simon.