Extremely Long Apo Ronars?

[sculptorBradP]

I have the 760 Apo Ronar CL barrel lens, mounting flange thread is M90 x 1. As the mounting flange thread is M90 x 1 - will an Ilex no. #5 hole - 85.47mm / 3-inch 3/8" hole on a Linhof Kardan lens board 161.925 / 6-inch 3/8" outer board dimension (I have not purchased the Linhof board yet) only fit the lens with the Ilex no. #5 shutter attached or will the Linhof Kardan board outer dimensions 161.925mm with the Ilex no. #5 hole 85.47mm also fit the 760 APO Ronar CL as a barrel lens without the shutter attached? I have a mounting flange already though a Sinar variant - mounting flange included that accepts with this flange the 480mm Apo Nikkors and the 600mm Lomo lenses. A Schneider Lens Mounting Flange - 90mm Diameter x 1" is also available – (I have not purchased yet) - if advised as a better choice - proven solution with use on a Linhof Kardan board and not problematic on this Rodenstock 760 APO CL Ronar? Thought I would ask here rather than purchasing to find out., - Thanks, - Brad

[Dan Fromm]

I have the 760 Apo Ronar CL barrel lens, mounting flange thread is M90 x 1. As the mounting flange thread is M90 x 1 - will an Ilex no. #5 hole - 85.47mm / 3-inch 3/8" hole on a Linhof Kardan lens board 161.925 / 6-inch 3/8" outer board dimension (I have not purchased the Linhof board yet) only fit the lens with the Ilex no. #5 shutter attached or will the Linhof Kardan board outer dimensions 161.925mm with the Ilex no. #5 hole 85.47mm also fit the 760 APO Ronar CL as a barrel lens without the shutter attached?

Hmm. The lens' rear barrel will stick out behind the shutter if it is in shutter. If you attach an M90x1 flange to the board the rear barrel will stick out behind it. You have the lens. Measure the rear barrel's OD. That will be a hair smaller than the hole needed in the lens board. By the way, the Apo-Ronar brochure doesn't give the 760/14's rear barrel's OD.

[sculptorBradP]

Thanks, Dan

[sculptorBradP]

Looks like 79.375mm outer threads on rear. The outer lip of the Flange intended for a Sinar is 93.6625mm - where the hole lens board seems to be intended to cup.

[Dan Fromm]

Looks like 79.375mm outer threads on rear. The outer lip of the Flange intended for a Sinar is 93.6625mm - where the hole lens board seems to be intended to cup.

You just confused me. You may be confused too. WHERE are these 79.375 threads located? The brochure shows the lens' rear tube -- this is the lens' rear cell -- as smooth. The front of that tube is threaded externally -- size not shown in the brochure -- and screws into the back of the barrel or into the back of a shutter. I doubt it will go into an Ilex #5, could be mistaken. The barrel contains the diaphragm, is threaded internally at both ends to accept the lens' cells. Both are threaded externally to go into the barrel By the way, the brochure says that the flange, into which the rear of the barrel screws, goes into a 93.5 mm hole. That's Rodenstock's flange, there's no guarantee that any other maker's M90x1 flange will fit a 93.5 mm hole.

You seem to be overthinking things. Just get an M90x1 flange and have a board bored to accept it. Also have the board drilled and tapped to accept the screws which will hold the flange to the board.

How are you going to time exposures? You mentioned an Ilex 5. The lens' cells' threads will be metric, Ilex shutters are Imperial.

[sculptorBradP]

The smooth portion measures 84.9mm ,

[sculptorBradP]

[Dan Fromm]

Why two flanges? Either will do. And that answers the question. If you want to mount the lens on a lens board, have the board bored to accept the flange you want to use, drilled and tapped for the six little screws, and you're set.

[sculptorBradP]

Proceeding from end back toward front - furthest back - smooth - 84.5mm width / furthest back thread - 88.1mm width thread / next smooth - 88.9mm width / next thread - 92.868mm width

[sculptorBradP]

You got me, I received it from the seller on Ebay yesterday as such. He said only that the flange was used for a Sinar. I am not familiar with how this lens was intended to set onto the lens board correctly, as well as only looked up online forums mentioning that the Ilex no. #5 was the best choice for a shutter.