Lens is fantastic. Can't answer your other question though. This is the type of 50 that really shines stopped down, great for landscapes but it seriously ain't too shabby wide open either (being known for its wide open sharpness). Sits at a nice compromise between great IQ and size.
My 5D seems to hang the mirror on every single iffy lens out there
This one is no exception... not that it ever stopped me though
I just unscrew a little to release the mirror and carry on.
I agree with Mat. I've had my 5D and 1DsIII mirros hang on some lenses (which I don't especially like), and it hasn't caused any issues. OTOH, water does cause issues for a 5D.
It depends on how big the obstruction is. I know someone who ruined his 5Dmk2's mirror with a Rollei lens, where I believe the mirror must have struck the rear of the lens when going up. With the Contax lenses are known to cause mirror problems, the 5D's mirror usually only hangs when going down, after the exposure, which isn't really harmful.
Also some 5D's had the mirror glue problem that the glue came undone after prolonged periods in humid environments, so I imagine that hanging the mirror wouldn't help with this specific problem.
Having said that, over the years I have slapped my 5D's mirror silly on an assortment of lenses of all makes and sizes and it's still going strong, so I wouldn't worry too much about it.
