[Leica] Single-Frame 35mm Camera

[nicholsj at edge.net (Jim Nichols)]

A week or so back, someone asked about the suitable focal length for a 
standard lens for a single-frame 35mm camera.  I responded that, based on 
the diagonal of the film image, a 35mm lens is appropriate, and included 
that I have a Mercury II single-frame camera which is equipped with a 35mm 
f/2.7 lens.  Sonny C. saw my comment and said he also has such a camera, and 
wondered if I ever shot any pictures with it.  It has been sitting in a box 
in a closet for at least 25 years, but I thought I would give it a try.

There was a pre-war version of the Mercury that used a special film.  In 
1945, the Mercury II was produced, incorporating standard 35mm film 
cartridges and a hot shoe for flash.  The unique shutter is of rotary 
construction, of steel, and moves a window across the single-frame opening 
in 1/20th of a second.  Exposure is varied from 1/20th to 1/1000th of a 
second by varying the slot width of the shutter as it crosses the film 
opening.  The semi-circular enclosure on top of the camera is necessary to 
accommodate the movement of the shutter.  The camera body is of cast 
aluminum, with very close tolerances, but the bare aluminum is subject to 
corrosion, and many of the remaining examples are too corroded to be useful. 
  With the single-frame format, one can get 65 exposures on a 36-exposure 
roll of film.

It should be noted that the camera has no rangefinder, and no exposure 
meter.  Focusing is by scale setting, and the camera includes detailled 
depth-of-field tables on the front and back plates.

I loaded it up with Kodak B&W400 C-41 film and tried my hand at using it.  
For a guy like me with tri-focals, the viewfinder is a real pain.  After 
guessing at some exposures, I reverted to a small, clip-on meter to help.

Not wanting to take the time to shoot the full roll, I pulled the film after 
about 30 exposures and took it to Wal-Mart 1-Hour Photo, explaining that the 
images would be different from what they normally see, but asked for 
developing and transfer to CD.  When I picked up the film and CD today, I 
found that my exposure guesses and the lab's transfer to CD both had 
problems.  The unusual spacing of the images will not convert easily to two 
images per normal frame, so I got some chopped up files.  However, there 
were some useful images that serve to demonstrate the camera's capability.   

I mention the lab problems not as criticism, but to point out the problems 
that are encountered when one leaves the "beaten path" of photography, 
whether it be the Mercury II or the Leica single-frame version that was 
mentioned on the LUG a few weeks ago.

Photos of the Mercury II and examples of its photos are posted in my 
gallery, as given below.  I realize this is OT, but other comments will be 
welcomed.  Have a look.

http://gallery.leica-users.org/Musings/Mercury21 

http://gallery.leica-users.org/Musings/Mercury20 

http://gallery.leica-users.org/Musings/100_Hour_Inspection

http://gallery.leica-users.org/Musings/Helicopter9 

http://gallery.leica-users.org/Musings/Helicopter10 

http://gallery.leica-users.org/Musings/Steeple12 



Jim Nichols
nicholsj@edge.net