The Berlin phenomenon

[P3D Paul S. Boyer <boyer@xxxxxxxxxxxxx>]

It is written:
"While doing some stereo editing I noticed a curious phenomenon
related to
LCS glasses. Remember they alternate left and right sequentially.
With my
screen resolution at 1024 x 768, the maximum vertical refresh for my
monitor
is 75 Hz. Stereo images viewed at that resolution have noticable
flicker,
though it can be ignored.

The observation was made while attempting to freeview an image pair
in the
image editor (not stereo mode) while still wearing the goggles.
During the
moments that my eyes dissassociate with direct 2D viewing of the
screen, and
seek the point where the stereo recombines forming a fusion lock for
the
vision process, the alternate nature of the flickering goggles
becomes
directly observable. I literally feel the back and forth switching.
As soon
as my eyes lock onto the stereo pair, this awareness goes away.

Startled, I tried it several times. Each time, while my eyes aren't
seeing
and locked onto similar data, I can *see* the glasses alternating
back and
forth quite clearly. (perhaps the only consistently observable
phenomena
available to see?)  It goes away with any image fusion whether 2D or
stereo
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available to see?)  It goes away with any image fusion whether 2D or
stereo
viewing though the images being fused are themselves still
alternating
because of the glasses.

Larry Berlin."

Yes, this is to be expected.  When you are using fused vision there
is a flick at the beginning of each frame, altternating right and
left.  This is true whether you have viewed true stereo, or simply a
pair of identical 2D images.  Before fusing, each eye sees one big
flash as each image appears for that eye.  I think that you can see
that when fused the flicker frequency is thus double.
Nothing wrong with you eyes here!

--Paul S. Boyer   <boyer@xxxxxxxxxxxxx>


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