Was da C/Y Planar 50 1.4 und den 5D Spiegel betrifft, schaut mal hier:

http://slrlensreview.com/web/carl-ze...ns-review.html

Zitat: "
First thing first however. If you are planning on using Contax Carl Zeiss Planar 50mm f/1.4 on your Canon 5D, be forewarned that MM versions of the lens do not clear the camera's mirror, causing it to lockup during shooting. There is no universal opinion even about this issue and it looks like there is some variance in the construction of Canon 5D's mirror box that sometimes causes this issue. Another possible explanation is the thickness of your Contax to EOS adapter since there does seem to be a pretty wide variance in the thickness of adapters currently being sold all over the Internet. One way or the other, you should certainly be careful so you don't damage your camera - two different copies of MM lenses tried in this test did lock up the mirror. On the other hand, AE versions of 50mm Planar f/1.4 don't seem to have this problem in general - at least there have been no reports about mirror lockup with AE versions of this lens, plus four different AE samples tested here (including an anniversary edition sample) worked just fine."
also - es haengt davon ab.
Was diese Kommentare bzgl. der verschiedenen Adapterdicke betrifft (auch fuer andere Objektive) so verstehe ich die nicht. Der Abstand der Ruecklinse vom Sensor ist doch bei korrekter Fokussierung auf Undendlich gleich. D.h. entweder es schlaegt bei korrekter fokussierung auf Unendlich an oder nicht.