As the title says -- I'm like to mount my 150 Xenotar on a helical for use with my Cambo Wide. Buying something off the shelf would be much much easier...
As the title says -- I'm like to mount my 150 Xenotar on a helical for use with my Cambo Wide. Buying something off the shelf would be much much easier...
They are ill discoverers that think there is no land, when they can see nothing but sea.
-Francis Bacon
No. They are virtually all for a 0 shutter from Schneider and Rodenstock. You might be able to scavenge a focus mount from a Linhof 45 Aero Technika EL but the lens that it is mounted to is a five figure lens and not a consumer photography product. Additionally, since it is for aerial work it only focuses to about 500' and has locking stops at various distances. It is also shrouded in a very large metal barrel which is virtually part of the focus mount and it mounts via a large breech lock mount to the camera body.
Off the big auction site, I picked up a generic helical focusing mount made for a 90mm lens. Focuses down to 1.5 meters with a 90mm lens. Measured it and if you enlarged the hole in the front, a Copal No. 3 shutter will tightly fit. Someone like S K Grimes could easily thread the front to fit a Copal No 3 shutter. Seller was and is ecbuyonline2008. Unit is very well made.
I have a Pentax 67 helical focusing mount threaded for a Copal 3 shutter in the front. Perhaps that could be adapted more easily. The overall length is 140mm. If the mount is removed, I think it would work for the 150mm. Send me a PM if you're interested.
Kumar
I recently picked up a Bronica S-series system(with an S2a and C body). These bodies are interesting in that the focusing helical-while removable-is meant to stay with the body and the lenses are interchanged inside the helical. The helical has a fair bit of travel-the lenses I have run from 50mm to 150mm and it's able to focus the 150mm to around 4'. The scale is marked to go out to 250mm, and it will go to 8' I think. Aside from the bayonets to hold the Bronica lenses, there is also an internal screw thread that visually looks larger than a #3, so a good machinist could probably make an adapter ring.
I only mention all of this because these are inexpensive. I paid $300 for my system(S2a, C, 50mm, 2x 75mm, 135mm, 150mm, extension tube set, bellows, a couple of extra inserts, and other odds and ends), although indications are that I probably got a decent deal. It's actually a great MF system with outstanding Nikkor optics even if a bit quirky, but I expect that the helicals could be very useful if you went to the trouble of of making up a way to fit them.
But you would not focus to infinity with a 150 on a 90 helical unless you extend the length of the tube to match the flange focal length of the 150.Originally Posted by Greg
Correct... You actually have to extend the distance behind the helical to be able to focus at infinity. The helical tube is very generically made and needing to be adapted for final use. "You get what you pay for". Actually the construction of this helical tube is amazing well machined and finished, way better than what I expected to get.
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