Lens adapter at infinity ?

Jim Schemel · Joined: 21 Jul 2009 Posts: 109 Location: United States

I have a MF lens with an EOS adapter on it that just grazes the mirror when at infinity focus, and it does so only on the mirror return.Is this something that i should worry about? It really does not bother me, because the mirror usually finds its way back on its own.I guess my question is - will this cause any problems in the long run?
I'm sure that i am not the only one who has experienced this.Any thoughts or suggestions would be greatly appreciated.
-Jim

PaulC · Joined: 23 Dec 2008 Posts: 2318

I've not heard of anybody risking continual use of a lens with that problem. There is - somewhere here I think - a simple guide to shaving the edge of a 5D mirror to allow use with lenses that foul it. The solution doesn't seem to be as difficult or risky as it sounds.

I just stuck to lenses that don't have mirror problems. There are lists of those.

rick_oleson · Posted: Sat Oct 17, 2009 5:56 pm Post subject:

It's not something that I would risk a $3000 camera on, but I'm a cheapskate. If it is really only contacting the lens on the down stroke, it's probably not doing any harm, but my guess is that it's hitting on the upstroke as well, just with enough power to plow on through - this is likely to cause problems down the road. It sounds like it's not hitting by much - can you do a bit of shaving on the rear rim of the lens, rather than on the mirror? I like to do my tinkering where the risk and cost is lower (like I said above, I'm a cheapskate)