How to Mount a Pneumatic Shutter from Bausch and Lomb

[geyes30]

Hi I just purchased a lens on eBay and the lens is largely unmarked, apart from the Bausch and Lomb pneumatic shutter, as well as a Premo label. Unfortunately it came without a lens board, and also has no mounting ring/flange. I am not familiar with older lens designs, so I am not sure how I should mount this. Are these lenses typically mounted directly onto a lensboard through a threaded flange, or are they mounted like modern lenses, using a mounting ring (I suspect the former, since the threaded portion is not really 'raised' off the back of the shutter to allow for the thickness of the lens board)?

I have also measured the threaded portion and found that the minor diameter is approximately 62mm while the major diameter is around 63.5mm. Does anyone know where I can find specifications for the thread (is it English or Metric? What is the pitch? etc.)?

I have attached a picture to this post. Hope someone can help me with this! Thanks!

[Jon Shiu]

It does screw into a flange that is attached to the front of the lensboard.

There is a discussion on flange threads on the skgrimes.com site. There are also B&L catalogs on cameraeccentric.com. It is likely to be some type of inch measurement like 2-1/2".

I do have a flange that measures about 62mm, which might fit, or might be slightly too small. http://www.largeformatphotography.in...hlight=flanges

Jon

[geyes30]

HI Jon,

Thanks for your reply! It's extremely informative and I was even tempted to get something from skgrimes. But considering that the lens cost me 50 bucks, I don't think I want to spend another 40 to mount it. What I did in the end was to cut a hole in an artist's canvas board a little smaller than the actual lens thread and screwed the lens in. I also stuck a piece of foam core behind the board to form a 'light trap' and provide rigidity. The result looks terrible, but is perfectly functional!