T3D Re: Re acuity enhanced with binocular vision

[Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 4:22 AM -0700 3/20/98, Peter Homer wrote:
>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could be withdrawn to allow all the light straight up the one tube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

Yes, perceived brightness is not necessarily related in a simple way to
light level or detectability...

-Jim C.

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Jim Crowell
Division of Biology
216-76
Caltech
Pasadena, CA
(818) 395-8337
jim@xxxxxxxxxxxxxxx



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