P3D "Bowl" distortion in viewers [resend]

[erker@xxxxxxxxxxxxxx (Greg Erker) (by way of wier@xxxxxxxxxxxxxxxxx (Bob Wier))]

Larry Berlin wrote:
>*****  Go try it for yourself. A flat picture of full frame dimensions
>presented in a Red Button will curve towards you in 3D space on all edges
>proportionately. I haven't examined the 2D distortions in each side, only
>examined the effect of stereoscopically flat surfaces (two images of the
>surface with zero parallax) as they are seen when using both eyes looking
>into a Red button viewer in a normal fashion.

  Very cool idea. I've never noticed bowl distortion
in my RB or any other viewer, so I guess I'm not
sensitized to it. OTOH I'm very sensitive to film
grain and go to great lengths to minimize it
(Velvia in medium format and Kodachrome 25 in my
Realist).

  I don't normally have any flat photos to view
but I did take a test roll (w/o moving camera)
with my (then) new-to-me Bronica S2A.

  I'll have to mount one of those "pairs" and
see what kind of distortion my MF viewer has.
I even have two sets of lenses to try with
it (AS&S 40x84's and Edmund 36x82's).
I'll let you all know the results when I get
it done.

(P3D is a great list!)

Greg E.

http://www.angelfire.com/ca/erker
(see my MF viewer and other things)




------------------------------