Exakta lenses on 5D Mk. II-I thought I was an expert, but...

[eggboy]

...it seems I'm not. I've been shooting with 10D - 40D for years, and have only heard that certain lenses have issues with full frame.

I got to use a rental Canon 5D Mk. II for a some video footage for a project I'm helping with. I was excited to try filming some video and also shooting full frame with my pre -war Primoplans/Biotars/Tessars etc.

But they all fouled the mirror. These were all 50-58mm lenses. Looking closely, it's the back of the Exakta lens mount itself that hits the mirror at the very top of it's travel. Even when the lenses were racked to their close focus distances.

I thought these lenses were fine as they don't really have any elements that stick out. And, it's the lens mount lugs themselves that seem to be the issue.

When the adapter is screwed on by itself, there is no problem.

I have 2 different adapters, one with the set screw, one with the little locking tabs. Neither one is too thin, as on a 40D all the lenses don't quite hit infinity.

Lenses used:
1938 Biotar 5.8cm/f2
1937 Primoplan 5.8cm/f1.9
1936 Tessar 5cm/f2.8.

Could it be camera variance?

Was thinking hard about going full frame...tho' with a used 5D Mk. I as I don't need video. Do I have to shave the mirror to be able to use ANY Exakta lens?

[calvin83]

[eggboy]

Thanks for the reference to that thread...

Where do I get a 'thick' adapter? Luckily for me, both the pre war Biotar and Primoplan are fairly easy to re-adjust infinity focus, so the few tenths of a millimeters I'll need should be doable.

I see there is a group order for adapters...does this include a 'thick' adapter, and do I have to quickly post a bunch of "+1" replies to get to the 100 message level so I can access this order?

[calvin83]