Tips on servicing 1890's Bausch & Lomb Unicum Shutter ?

[Luddite Frank]

I picked-up a Bausch & Lomb "Unicum" shutter, with a "Special Rapid Rectilinear" 8x10 lens.

The latest patent date on the shutter case is 1891; shutter speeds are marked:

T - B - 1 - 1/2 - 1/5 - 1/25 - 1/50 -1/100

F-stops: 8 , 16, 32, 64, 128


The glass is good, and while the shutter operates, it is pretty sluggish on the "instantaneous speeds".

Also, the diaphragm is very stiff to open & close...

This shutter has the speed-set at the top of the housing (12 o'clock), and has two curved arms, one on each side, that connect to nickel-plated damper cylinders, on either side of the lens mount.


Any suggestions on how to CLA this artifact ? 🙂

Thanks...

Luddite Frank

 

[RF-Addict]

I would send it to Flutot's camera in California. Carroll has very reasonable prices and does a great job - here is the website:

http://www.flutotscamerarepair.com/

 

[venchka]

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Join The Large Format Forum

I would send it to Flutot's camera in California. Carroll has very reasonable prices and does a great job - here is the website:

http://www.flutotscamerarepair.com/

First of all, what RF-Addict is true.

Secondly, this shutter may require tubes and air pressure to operate. That's just a hunch becasue I have a similar aged lens & shutter at home. Anyway, if you post tihs at the Large Format Forum with pictures somebody will know exactly what you have, how to fix it, how to use it, etc.

PS: Any clue what the focal length of the lens is? Those old Rapid Rectilinears are great! I have a 150mm set from a Kodak 3a from around 1913. Looking forward to using it soon.

Good find!

 

[Luddite Frank]

Not sure what the FL of this lens is ... I'm guessing probably in the vicinity of 12 inches ?

I did find a little background info about the Unicum via Google... as you face the lens, the cylinder to the left of the lens is for the air-bulb remote release - this has a little nipple at the bottom, to "Grab" the pneumatic hose.

The cylinder on the other side regulates the shutter speeds: depending upon how "fast" a speed is selected on the dial, the lever/piston is raised a pre-determined amount - the slower the shutter speed selected, the higher the piston is raised when the shutter is cocked.

When the shutter is tripped, the timing piston exhausts the air in its cylinder via a bleed hole at the bottom. The more air that has to be exhausted (greater piston travel), the longer the shutter stays open ! 😎

Pretty clever...

This was from an era (pre-electric/ electronics) when many mechanical / remote activities were performed by pneumatic "servos" - things like player pianos (work on "suction"), pipe-organs (the French pioneered the "tubular-pneumatic" system, which allowed the keyboard to "talk" to the pipe chests via pouches, lead tubing, and pneumatic "relays", thus liberating the console from it's mechanical hook-up to the pipes, as in Bach's time), the pneumatic tube system for sending messages through large buildings (office bldgs, dept stores, bank drive-ups), and so-forth ...

Ah... the days before "electrons" did evereything for us ...


🙄

LF