Model - Rated Shutter Life Canon EOS Digital Rebel XS / 1000D - 100,000 Canon EOS Digital Rebel T1i / 500D - 100,000 Canon EOS Digital Rebel XSi / 450D - 100,000 Canon EOS Digital Rebel XTi / 400D - 50,000 Canon EOS Digital Rebel XT / 350D - 50,000 Canon EOS 50D - 100,000 Canon EOS 40D - 100,000 Canon EOS 30D - 100,000 Canon EOS 20D - 50,000 Canon EOS 5D Mark II - 150,000 Canon EOS 5D - 100,000 Canon EOS 1D Mark III - 300,000 Canon EOS 1D Mark II N - 200,000 Canon EOS 1DS Mark III - 300,000 Canon EOS 1DS Mark II - 200,000 Another interesting source of information is this guys shutter life expectancy database.
This second source of information apparently collects peoples actual experience with shutter failures (and non-failures) and shows that few 5Dii shutters fail before 300,000 clicks - although Canons official rating for the shutter is 150,000 clicks.
Shutter and vibrationSomething that has crossed my mind is the possibility of some kind of image capture when tethered and in live view mode. After all, a series of images are being transferred across the USB link and in theory it should be possible to capture one to disk. Such an image may be at some reduced resolution (likely so, as this would drastically reduce the bandwidth requirements).
One possibility is to use the alternate firmware being developed by the Magic Lantern project. Although magic lantern was originally developed to support interesting video related features, the site says that effort has now been directed towards still photography, and in particular:Classic ML for 5D Mark II has extended bracketing and focus stacking functions.Amusingly, the project was originally called "5D Mark Free", but the developers thought maybe Canon might dislike this sideways reference to their trademarks and avoided any possible unpleasantness by changing the name.
A related project is the CHDK (Canon Hack Development Kit).
Feedback? Questions? Drop me a line!
Tom's Mineralogy Info / email@example.com