ERROR CORRECTION CORRECTION!
With regards to TECHNICAL DATA ERROR NOTED as per BIRDS AS ART NOTES
of
DEC 20, 2000, I received an e-mail from Pat Price. My response to his
e-mail follows. (Note: only those who truly understand exposure
theory
for color slide film will be able to follow the line of reasoning
below.
Those who cannot are urged to order a signed copy of "The Art of Bird
Photography" off of the web site and commit themselves to learning the
material covered in the chapter on exposure.......)
Hi Pat,
It is great to hear from you.
Re:
Pat: I was confused by your Technical Data Error Noted in your E-mail
today. You indicated that the correct exposure for the single Snow
Goose
in flight was 1/1600th at f5.6. That would not be a Sunny 16 exposure
for
Provia 100 pushed two stops. My numbers would indicate that if sunny
16
is
1/400 at f16 then at f5.6 (open up 3 stops) then the shutter speed
would
be 1/3200 as you originally had stated.
Artie: I do not follow your reasoning exactly, but you made me realize
that I had it right the first time; here is my reasoning:
While the theoretically correct Sunny 16 value (for EI 100 film at
f/5.6)
for a middle-toned subject is 1/750 or 1/800 at f/5.6 (depending on
1/3
or
1/2 stop increments), the practical sunny 16 for a middle-toned
subject
in all but the extreme brightest conditions is 1/500th or 1/640 at
f/5.6.
As we all (should) know, if you want the correct exposure for a
> brilliant
white subject in the same light, simply shoot one stop darker (John
> Shaw's
Sunny f/22 for brilliant whites). Therefore, the practical sunny 16
for
brilliant white subjects is 1/1000 or 1/1250 sec. at f/5.6.
Working from a starting point of 1/1000 second (for EI 100 film at
f/5.6),
which is my recommendation for Snow Geese at Bosque in full afternoon
sun
at about 3 p.m., we would get to 1/2000 sec. at f/5.6 for EI 200 film,
and
to (only) 1/3200 at f/5.6 for Provia F 100 pushed two stops (but rated
at
only EI 320; thus 1/3200 sec. not the expected 1/4000 sec. )
Thank you for making me realize that I was right all the time, but
just
too dumb to realize it! (Sorry Sandy.)
Thanks and best,
Artie, your friend and admirer from the cold Southeast!
TWO GREAT BIRD PHOTOGRAPHY WEB SITES
#1:Check out Russ Kerr's images at http://www.majestyofbirds.com
Russ's Great Blue Heron home page image is an absolutely stunning
painterly image. His ducks and raptors in flight are superb as well.
#2: Fortunately for me and my bank account, Robert Royce, long time
BIRDS
AS ART student, IPT participant, and a staunch photo.net supporter of
mine, makes a living playing English horn for the Columbus, Ohio
Symphony Orchestra.
You can view dozens of Bob's great images at his admittedly bare bones
web site: http://www.geocities.com/roysephotos
There are lots of great images here, but do check out the first
Mountain
Bluebird image: razor sharp male, 600 IS with 2X TC (does that sound
familiar?), with the bird tossing back a juniper berry. A truly
superb
image.
ANOTHER LENS FOR SALE
Mark LaGrange has a Canon EF 400mm f/2.8 L Image Stabilizer lens in
mint
condition for sale. You may contact him at
mailto:MarkCLagrange@AOL.com
Please do not e-mail me if the lens has already been sold. Thanks!
Best and great picture making to all,
Arthur Morris/BIRDS AS ART
