Summary of stereo slide mounts

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

While on the subject of stereo slide mounts, I would like to present a
brief summary of the different types available.  It is clear in my mind
that each type of mount has certain advantages and disadvantages.  I would
personally like to use all three basic types: cardboard, aluminum and
plastic (RBT).  It is better that people are informed about the
characteristics of each mount, rather than blindly use only one.

Here are some factors that affect the decision on what mount to use:  Cost,
convenience, accuracy, storage, risk of handling damage, final use (viewer
vs. projection). 

Personal observations, opinions:

- Cardboard mounts:  Heat-seal cardboard mounts have been the standard of
routine mounting for many years.  They are inexpensive, simple and look
good.  With a little care it is possible to mount in these mounts with
acceptable accuracy even for projection.  Slip-in mounts is a convenient
solution for no-brainer mounting but comes at a cost of both money and
accuracy.  "Spicer" (tape-shut) mounts do not have mounting guides to set
the chips (which makes mounting a bit more complicated - but clever
solutions have been discussed in P3d) but come in an amazing variety of
sizes.  One general disadvantage of cardboard mounts is that edges are
always a bit fuzzy, plus, in a bright viewer, some light leaks through the
edges.  One advantage is light weight and low risk of damage (lack of sharp
corners).

- Aluminum mounts:  Aluminum mounts are thin, provide the best edge for
hand-viewer viewing and allow for accurate mounting.  Most aluminum mounts
(Realist, Albion, EMDE 7p) allow control of the stereo window and come in
different sizes.  Without any cover, one can stack hundreds of slides in a
small box (at the risk of scratching them with sharp mount corners).  Some
kind of cover is usually required, which adds to the cost and time. 
Choices of aluminum, cardboard and glass covers exist.  Glass-mounted
slides are best for protection from handling (fingerprints) and have been
the standard for treatment of salon-quality (this is changing) or valuable
slides but they are not maintenance-free as the glass tends to fog
internally with time.

- RBT mounts:  At a slightly higher price (for one piece mount) they offer
accurate and quick mounting.  System of sliding rails makes adjustment of
the stereo window quick and simple.  System of step-wise horizontal offset
makes it very easy to use with cameras that have a fixed offset between
right and left chips.  Rotation correction and non-standard cropping are
not easy.  Rigid construction and good selection of sizes.  This is the
best mount to use to put together a slide show mounted for projection in
the least amount of time.  They are lighter than glass-mounted slides, no
problem with oils or dust trapped in glass or glass breaking.  Also smooth
edges reduce the risk of scratching.

George Themelis


------------------------------