More camera ideas and questions

[Brian Reynolds <reynolds@xxxxxxxxx>]

While laying in bed today trying to get some sleep (I stayed up waaay
too late last night trying to get some software to compile) I came up
with an idea for a handheld stereo/wide-angle flat 4x5 camera.  The
idea is to get both images on a single piece of film so that alignment
during mounting (by referencing the edge of the film) will be easier.

Given minimal (tilt on front and back, mostly for architecture) or no
movements and the short focal lengths involved (my Lubitels have 75mm
lenses, my Yashicamat has a 80mm lens and my Saturn MF viewer has 84mm
lenses), I figure a short (square) monorail camera with a bag belows
(made from darkroom cloth and nylon and elastic strings to keep it
from collapsing into the light path) should be hand holdable.  A wire
frame viewer, buble level and focusing marks on the monorail (for both
actual distances and hyperfocal distances (indicated by f-ratios))
complete the camera.

This leaves me with a few questions before I start detailed drawings
(anyone know a good drafting program for X11/UNIX) and cutting wood.

Does anyone have experience taking apart the lenses/shutters on a
Lubitel.  I figure that at $40 a piece they are the least expensive
lenses (with shutters) I'll find for experimenting with.  Also, does
anyone know if the viewing lenses in the Lubitel are the same as the
taking lenses?  If I can use the lens elements from the viewing lenses
in the shutter that gives me more lenses to use to match focal
lengths.

Is anyone on the list shooting stereo on 4x5 film and trimming it down
to fit the 6x6 mounts?  The original point of this project is to get
both pairs on a single film strip, but building a 4x5 back is easier
than building a 6x12 rollfilm holder.  The Horeseman 6x12 rollfilm
holder for Graflok backs (the only Calumet has in their catalog) is
$850 new, and I don't expect it's much cheaper used.

How do you calculate for depth of field when the final image will be
seen with a viewer instead of projected or printed?  A simple solution
would be that the circle of confusion could be bigger, but how much
magnification does the viewer have?

Finally, is there an easy way to figure out how far beyond the
infinity point you have to move the lens in order to focus at a
specific distance?  I know from reading various large format books
that in order to have a 1:1 image on film the lens must be twice the
focal length from the film and the subject is one focal length from
the lens (and the exposure has to be longer).

I'd also be interested in hearing about source for cheap MF and LF
lenses of about 80mm focal length and cheap 6x12 camera backs.

PS: I ran out of disk space and the compiles I finally left running
overnight failed.

-- 
Brian Reynolds                  | "Humans explore the Universe with five
reynolds@xxxxxxxxx              |   senses and call the adventure science."
http://www.panix.com/~reynolds/ | - Edwin P. Hubble