P3D Pulfrich Effect

[Dave Combs <dcombs@xxxxxxxxxxxxxxxx>]

Ron Keas wrote:
>
>Thanks for the information on where to aquaria pulfrich glasses. While
>searching the web I ran across a web site that described how red and
>cyan lenses are better for pulfrich effect than the one dark lens. Does
>anyone have an opinion on this? The web page I refer to is -
>http://www.3dglasses.com/3dtv.htm

I visited the 3dtv web site and the sample images on their web site 
appear to me to simply be regular analglyphic images with the left and 
right colors reversed. I viewed the images just fine by reversing a pair 
of analglyph glasses.

>The information on that page claims that the one dark lens causes eye
>strain.  It is my opinion that the eyestrain most people experience from
>the pulfrich effect they've seen on network TV is caused by the improper
>use of motion direction. If the glasses are set up for let to right
>screen motion, to allow scenes with right to left motion is ignorant,
>but all of the productions I've seen make this mistake. How many of you
>have seen the expensive glasses that claim they make any TV show appear
>in 3-D?  I suspect this is another abuse of the effect by allowing
>people to assume that it doesn't make any difference which direction the
>subject matter is traveling.

I am not at all sure what the 3dtv folks are doing by combining reversed 
analglyphic glasses with the Pulfrich effect. I guess I'll have to try 
looking at my own Pulfrich video with a pair of these glasses to see if 
it actually works or not.

>One more question- What is the purpose of the light yellow colored lens
>on the left in the pulfrich glasses? I've found that I get a better
>appearing image simply by using a lens from sunglasses over one eye.  I
>also get good results from making a small aperture with my thumb and
>index finger.

In my opinion it is the difference in the amount of light entering the 
two eyes that enables the Pulfrich effect to work. So, I suspect that 
just about any combination of differing lens filters or light-limiting 
apparatus (iris or thumb-and-index-finger) will work--some just better 
than others. For extended viewing I personally like to simply use half of 
a pair of sunglasses. The quality of the lens is better than just the 
cardboard and plastic glasses.


Dave Combs
Combs Music International
421 Cedar Trail
Winston-Salem, NC 27104 USA
E-mail: dave@xxxxxxxxxxxxxx
Internet Home Page: www.combsmusic.com
800-932-6627 (USA & Canada)
336-760-0037
336-760-3855 (fax)


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