Can RB67 lenses be cocked by an external mechanism?

[ondebanks]

Here's an odd one for you.

 

I'm researching possible lenses for adaptation onto a Mamiya Universal (which

gives me all formats from 645 to 6x9). Any such lens must have a mechanical leaf

shutter, that can be cocked using some mechanism on the outside of the lens

barrel. Lenses for 4x5 inch LF cameras fit this description, but I'm also

looking at other medium format systems. MF lenses would generally be faster, and

generally have higher lp/mm resolution since they do not have to cover so much

film real estate.

 

The RB67 lenses would be excellent, especially since they cover 6x8 - so 6x9

should be doable as well. But am I right in thinking that the only way to cock

them is by using the pins at the inside rear, and that these pins would be

inaccessible on an adapted lens? (unless you dismounted the lens every single

shot?!!)

 

Thanks for any responses.

 

Ray

[erie_patsellis]

Ray,

I built a lensboard for RB lenses to mount on my toyo, it's doable, depends on how mechanically inclined you are.

 

 

erie

[mark liddell]

Depending on your budget I'd look at digitar lenses many of which can cover 6x9 even with limited movements and the performance is about as impressive as it gets. Not that fast though.

[denys_meunier]

Hi,Ray,I don`t know if mamiya 645 lens can work for your mount but those leaf shutter lens can cork external,I think you can have 3 lenses,the 70 ,80 and 150 leaf shutter possibility with external corking lever.

 

try to help, fotoman

[denys_meunier]

oupsssss,not corked,but cocked

 

sorry,fotoman

[erie_patsellis]

Ray,

I put together a couple of pages on my site highlighting what you need to do.

http://www.eriepatsellis.com/rb_info/lensboard1.html

 

erie patsellis

[ondebanks]

Erie, many (belated) thanks for your link! You came up with a clever solution for your view camera. In using your setup, what have you discovered regarding the image circle of the various RB67 lenses?

 

Thinking about my adaptation idea again, I realised that I made one silly oversight - even if I could solve the lens cocking issue, I would still have no way to focus the RB67 lenses on the Universal, unless I were to scavange the barrel of a Press lens for its mount and focusing helicoid.

 

I realise now that it would be a lot simpler to just get an RB67 ProS/SD body and use my f-l-a-t Press film backs on it, up to 6x8, via the P adapter that I already have. OK, then I would be basically buying into the RB67 system for everything but the film backs, so I would have greater bulk & weight, mirror slap, and SLR instead of rangefinder composition; but it would be a combination that Mamiya designed, rather than a hack on my part. If I really wanted a particular RB67 lens badly enough (say one of the APO telephotos), I guess it would be worthwhile. That RB67 chimney magnifier with the built-in PD-meter looks nice, too...maybe some day, some day.