Re: [photo-3d] questions about formulas

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

>1)  I have a 35mm realist with which I like to make
>holmes type views.  My camera is 35mm f.l. and my
>holmes stereo viewers are of focal length many times
>longer, is there an adjustment I can make to
>compensate for this difference? (I'm using the formula
>on Deering's web site.)

You have not taken into account the magnification
(enlargement) during printing... 

What is your goal?  To match the FL of your camera
with the focal length of your viewer?  Because your
negatives are magnified when printed, you will have
to multiply the FL of the camera by the magnification
factor.  For example, the vertical dimension of the
35mm negative is about 1 inch.  If your (untrimmed) 
prints have a final vertical size of 2.5 inches, then
the magnification (enlargement factor) is 2.5X so
the effective FL of your camera is 35mm x 2.5 = 87mm.
Do you know what the FL of your viewer is?

George Themelis