The first thing for astrophotography is to have a detector. Naturally it is now possible to buy all kinds of official detectors, even for amateurs. It is however more interesting to do some experiments yourself with off the shelf webcams. So that is what I will try to do at first. And maybe I can find some interesting webcams on a local garage sale.
I have as additional stumbling block that the webcam must work together with my Mac. And that means that I not only can see the images, but that there is an application that can tweek the webcam.
I have three webcams around: the a Logitech QCVC-USB-1 (QuickCam VC), a Trust (can not find it) and an Macally IceCam. I never managed to get the Trust one working and the Logitech webcam stopped working after my transition to MacOSX. For Trust and my Logitech there are no official drivers. There are two driver sites for MacOSX available: macam and ioxperts. The macam-driver does result in an image with the QuickCam, but nothing can be recognized. I think it some digitisation issue.
So that leaves me with the IceCam by Macally. This camera is recognized by MacOSX as Product ID:0x6007 and Vendor ID:0x0c45 (Sonix Technology Co., Ltd.). According to the website it is a CMOS camera with a resolution of 352x288, so some 100k pixels. And it takes movies up to 30 fps in CIF.
The Icecam comes with an application called Webcam Monitor (version unclear, latest update 2/16/2008). This application says that it is connected with a TAS5110D webcam created by Taiwan Advanced Sensor. And I gather that this is the CMOS-chip itself. This one is connected to an USB-controller called SN9C101 created by Sonix. Unfortunately I can not find any datasheet on the sensor and the manual does not offer more info. I would like to know the sensitivity and the dimensions of the pixels. Similar detectors have sizes of 2,6 by 2,1 mm2 with pixel sizes of 7,25x7,25 µm2