P3D Re: Stereocard to slide project

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

>I would like to convert [stereocards] to slides
>and project them as a slide show, possibly
>interspersed with modern views of the same subject.

>So advice please, especially on the following
>1.Choice of film

You can use either regular daylight color slide film (Kodachrome, 
E6, etc.) or black and white film.  If you go with B&W film you
don't have to worry about the color of the light source, just make
sure that the film does not depolarize the light.  If you go with
the more convenient color slide film then you will have to worry
about the color temperature of the light source.

1B. Illumination

Can use a flash at 45 degrees and not too close to the card to
assure even illumination, or two flashes at 45 degrees.  Also
a 3200K tungsten light with a 80A (deep blue) color correction
filter, or regular tungsten light bulbs with more blue filters
or even light from a window and a cloudy sky (must be common in
England, right? :-))

>2.Choice of lens

A macro lens would be nice or a regular normal lens with a 
close-up filter.

>3.Is a copy stand essential or can I improvise?

You can improvise.  A tripod would be OK too (I have used my
Bogen tripod for this purpose.)

>4.Choice of mounts

If you decide to keep the entire square format, the Realist
mounts should be OK.  If you want to crop the top or bottom
then you could use a 7p mount too.  Albion or RBT mounts are
fine.

The following was posted a few months ago on the same subject in
tech-3d...

=========

>I'm going to use a ring light...

Not sure about that.... Ring light comes from the top, around the
lens, right?  It might cause (well, it will cause) reflections
in the glossy surface of the prints.  You might want to try two
flashes at 45 degrees.  One flash should also work if it is not
very close to the prints.  I have used one flash successfully.
Other ideas are natural light (but watch for color balance, 
especially blue from sky) or photofloods.

>- Should I simply center each image in the view finder and fix up
>  the window on mounting

Yes, that's what you should do.  With the copied slides you can 
fix that window which is in the wrong place most of the time!
Also, remember that some cameras do not show 100% of the view 
photographed.  

You will have to decide if you want to include the arch or not.
(I'd rather leave it out if I have a choice).  You might try some 5p 
and some 7p compositions.

>- I was planning on using a straight edge for the bottom of the
>  card and simply slide the card from left to right when copying
>  each image.  

Yes, that's the way to do it!  Aligning the straight edge might be
a problem since you will not see it in the viewfinder... But once
aligned, you go on shooting without change.

>...do I need to watch for problems of
>horizontal alignment or rotation with the original images, or
>are these problems rare with such cards?

These problems are rare with good publishers (Keystone, U&U) but I have
encountered them with some second class publishers ("Realistic Travels")
    
> BTW -- I'll be using Agfa Scala 

Why?  Any color film should do equally good job IMO, plus capture some
of the original antiquish colors of the card.  One advantage of B&W
film is that you don't have to worry about colors and you could use
any source of light you want.

One last point:  Most cards are curved.  These are copied better if
held flat.  I have built a jig that holds the cards flat for copying
and the releases them when done.

Good luck!

George Themelis


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