T3D Re acuity enhanced with binocular vision

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

This is interesting because it used to be thought that there was some loss
of perception with a binocular or is it biocular microscope .At any rate
one which splits the image between the two eyes , the argument being that
the brain does not combine the intensities from the two eyes, if you shut
one eye the image does not get any darker. So anything that splits the
image between two eyes should halve the intensity, this was probably more
important in the early days of microscopy when light sources were weak.
Partly for this reason early binocular microscopes were asymetric with one
tube straight and the other raked at an angle to it and the beamsplitter
could be withdrawn to allow all the light straight up the one tube
converting it to a monocular for more "critical" work. The fact that they
are are no longer made that way suggests that it was later found
unneccessary.   P.J.Homer



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