Q: does CZJ Biotar 1.5/75 (thick one) hit mirror on EOS 5D?

[mflex-on]

or better asked: does mirror of EOS 5D hit the rear of CZJ Biotar 1.5/75 (thick one)?

[Orio]

Yes, mine does at infinity with the 5DMkII
My 5D is shaved so I can not say about it unshaved, but I guess it will do like the 5DMkII or even worse.

P.S: I have an Exakta Biotar. Maybe a M42 Biotar does differently.

[bob955i]

I have a '06 vintage 5D with an unshaved mirror and my fat Biotar 75 M42 mount doesn't foul. Works a treat with a Kood adapter.

A quick and painless check before you mount the lens to the camera is to see by how much the rear of the lens protrudes through the adapter when at infinity - anything more than 1mm is likely to cause problems with an unshaved mirror.

Another method is enable the MLU on the camera, focus on something close and enough to take the lens away from infinity, fire the mirror, refocus to infinity and then fire the shutter. That way, if the mirror's going to hit, it'll do it on the return and you won't damage it. That said, you have to make sure that the rear lens doesn't stick too far out as you don't want the mirror hitting that...

The latter doesn't apply to the late Biotar 75 though.

[fates]

Good advice Bob!
When the mirror does hit on the 5D mkii, it doesn't seem to have the force and weight behind it to cause too much damage if it makes contact a few times...