P3D Nu-View 3-D Adapter tests

["H a r o l d B a i z e" <baize@xxxxxxxxxxxxx>]

Well it rained again today in Berkeley CA! However, 
just before it started to pour I managed to put the 
Nu-View stereoscopic camcorder adapter through a few 
tests.

I'm happy to report that the concerns expressed by 
Scott Ressler and Mike Watters about magnification
differences were not noticeable and did not make close 
up shots difficult to view.

Scott Ressler wrote:
>The sales rep proudly announced that you can use the
>convergence adjustment to get excellent close-ups down 
>to 3 or 4 feet, but then showed visible irritation when 
>the engineer countered him, explaining that at distances 
>closer than 7 or so feet, you begin to notice the 
>magnification differences.  

To test this problem I set objects at 3, 4, 5, 6 and 8 feet 
from the camera position. Video of a 3 inch tall object at 
a distance of 3 feet could be zoomed to fill most of the 
screen and still was comfortable to view on playback. Given 
the resolution limits of my TV and camcorder I was not able
to measure the difference in magnification. I also recorded 
a dime at a distance of about 15 inches. At that distance there 
was a noticeable difference between the images. The dime 
measured 40mm and 45mm on the screen, a 1 to 1.125 ratio.
However the jumping image in still frame was difficult to
measure. 

Let's consider the math:
One frame was shooting at a distance of 15 inches, 
and the other at about 17.5 inches. The difference is a 
ratio of 1.16, close to the observed difference in the
size of the dime. In Mike Watters framework that is a 
16% difference. It sounds like a lot, but isn't, it is
noticeable but not unviewable. Yes, it is viewable even when
you get as close as 15 inches! At 3 feet the difference is 
6.94%, and that is hardly noticeable. The difference at 10
is only 2.083% and it would be hard to detected on even the
best TV screens. 

All the numbers aside, the real world viewing reality is 
that you can easily shoot a close up of a human face that 
completely fills the screen without any detectable 
magnification difference between the right and left images. 
I taped object the size of a human head from a distance 
of 3.5 feet, zoomed in until it filled the screen. The 
effect was great. Stereoscopic effect was very good.

It would seem that the sales rep was right to be irritated.

As in my earlier shooting the flicker was there but not 
a problem. I also found the 12 to 15 inch distant shoots 
of the dime were rather dramatic, although prolonged 
viewing might produce a headache. 

I do have a few things to complain about, maybe in my next
post.

Harolddd.



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