I recently acquired a Hassy V system 350mm f/5.6 CF Tele-Tessar and, as expected, it is heavy with a lot of weight sitting at the front of the lens that causes it to sag when mounted on the camera body affixed to a tripod. I'm therefore looking for a tripod lens collar. Kirk used to sell one but it's been long discontinued. There's a company called dslrkit that sells a dedicated lens collar that I've ordered but I'm frankly unsure about the build quality. In the meantime, I've been rummaging around the web it seems that the Canon tripod mount "D" ring made for the EF 100mm f/2.8L Macro IS USM might fit, but the numbers I've seen for the ring's interior diameter run anywhere between 68 and 72mm. The Hassy's lens barrel diameter is 71mm on the nose. I realize that a perfect fit is needed for the collar to do its job, but if it's only a little bit loose I can probably shim it up with some tape or felt.
If there's anyone out there with either the Canon 100mm f/2.8 macro (must be the "L" version) or the D ring, would you mind measuring the diameter of the lens barrel (or the inner diameter of the tripod collar) and letting me know?
Any other suggestions for solutions or work-arounds are welcome as well. Thanks!
John
