P3D Re: 3 red dots

[George Themelis <gthemelis@xxxxxxxxx>]

> I was wondering what the three red dots are on my realist 2.8
> and how they are used.  They were identified in Dr. T's book 
> as the "three dot system", but there was no description on how

> the "system" worked.

I am sorry... I'll try to correct in subsequent printings.  The
three dots were used to mark the "sunny day exposure" for the
ASA 10 Kodachrome available at the time.  So a small red dot was
placed at 1/50 shutter speed and one at f6.3 (I think) aperture.
 This is the sunny day exposure for ASA 10 film.  A third dot
was placed at the hyperfocal distance of the f6.3 aperture,
which is between 15 and 20 feet.  If on a sunny day you could
use these settings and get good pictures.  Dealers and owners
could easily put these dots in any Realist using nail polishing.

Of course, these three red dots SHOULD NOT BE USED TODAY!  (Is
that clear Chuck? :-))  But you can put your own dots depending
on what film speed you use.  I use ASA 100 film almost
exclusively.  The dots for me would be at 1/100 shutter speed,
f16 and 15 feet (the hyperfocal distance for f16 is around 8
feet but that's too close for normal stereo photography, i.e.
with infinity included in the picture.)

Another alternative of course would be to carry your digital
spot meter and your programmable calculator or laptop, but
that's an entirely different approach to this subject...

=====
George Themelis (DrT-3d@xxxxxxxxxxxxxxxx)
__________________________________________________
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com