Nimslo Conversions

[P3D Bob Aldridge <bob.aldridge@xxxxxx>]

->Date:   Tue, 18 Feb 1997 12:56:08 -0600
->From: P3D Greg Erker <erker@xxxxxxxxxxxxxx>
->To: photo-3d@xxxxxxxxxxxxxxx
->Subject: Re: Stereo depth (PHOTO-3D digest 1884)
->Message-ID:
-><97Feb18.125620-0600_cst.15229+631@xxxxxxxxxxxxxxxxxxxxxxx> 
->George wrote:
-> 
->>Bob, what I am looking for now is a camera that has a lens spacing
->>smaller than eye spacing, ideally between 40 to 50 mm.  This will be
->>for the close range shots which I enjoy so much.  I want this
->>camera to have an image size at least as wide as the Realist and,
->>if possible, a close focusing range of 0.5 m.  Am I asking too much?
-> 
->  The lens spacing may be possible from a Nimslo. Use only
->lenses one and three. Block off lenses two and four. Remove
->or move the septums (septi?) so that the two remaining lenses
->can form an image wider than 4 perf.
-> 
->  In an earlier private discussion with some other people it
->was felt that the Nimslo lenses could produce a 5 or 6 perf
->wide image.
-> 
->  The Nimslo is fixed focus but you could rig up a holder
->to place a closeup lens or two in front to bring the focus
->in to 1/2 metre.
-> 
->  I haven't done this so modifications are at your own risk.
-> 
->Greg E.
-> 
Well, I have modified Nimslos, and the usual is to use 36mm separation
with the lenses re-positioned effectively to where the outer septums
were - i.e. centred on the remaining full frame apertures.

The problem is that, although the lenses easily cover full frame, the
shutter blades are behind the lenses and progressively shade the image
area as the light gets brighter. In practice you will end up with no
more than 5 perf results. 

I have used a close up lens (72mm diameter in a spare filter mount
screwed to the front plate) on my Bobslo and taken a self portrait with
the camera held at arm's length. Came out rather distorted, but fun.

My favorite Bobslo version is the one I made for Derek Merfield, which
he uses in preference to his Custom Realist. It has a 50mm separation
and yields 25mm square chips. 25 pairs on a 36 exp film...

Bob Aldridge
Stereoscopic Society Projectionist
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