P3D PanX &Tech Pan

[John Toeppen <toeppen@xxxxxxxx>]

"At one time Panatomic X could be processed as either neg. or pos.  Is
it
still on the market???"  

Nope. No more 35mm Panatomic X ASA 32.  It did 300lp/mm
The advent of "T" grain (large silver halide crystals rather than
aglomerates)
gave us faster film with finer grain! It seemed too good to be true!
Tech Pan ISO 25 does 500lp/mm,  They also have some other fine faster
films.
All of these films can be reversal developed using kits.  A little bit
of research and you can make the kit yourself.  Old recipies lack
appropriate cautions and must have assumed good lab
practices....dichromates are wonderful but are high toxic if yellow
(hexavalent)rather than brown (trivalent and lightstruck). 
The classic reversal method develops the silver image without fixing,
stopping, or hardening,the silver is bleached out, followed by room
light exposure - exposing the remaining silver halide that you then
develop, wash, and fix. Reversals.
This kind of processing effort may be worthwhile for making holograms or
carbon transfers but why give up color in your slides?
Velvia is just too good.  If quality results are your goal use slow
color film.  Pardon me for rolling in my own concept of "purist"
stereo.  Please prove me wrong and post your examples. 
Some Kodak and Ilford slide films have pastel colors that are nice in
winter if you want to mute your colors and still use commercial
processes.
I could see where contact printing large negatives could be very nice in
B&W. Certainly, some of the old stereo cards are quite impressive
contact prints.  A Brewster style viewer could be used to view twin 8 x
10s"

John Toeppen
http://members.home.com/holographics/