Image Copyright 2002 Arthur Morris/BIRDS AS ART
Verdin, Tucson, AZ
Canon EF 500mm f/4 L IS lens, 2X II TC, EOS 1v.
Fuji Provia F 100 pushed one stop (at EI 200)
Flash as main light. Background exposure set manually
at -1/3 stop; 1/60 sec. at f/11
Here, I used CF-4-3 to AF on the eye and recompose
An e-mail from Bulletin Subscriber
Donald Barker with my response:
>Hi Art,
> I
know you cannot answer all inquires,
AM: That is correct, but I do
not mind answering fresh questions.
>but I really appreciate the
hints you give us.
AM: Thanks for your kind
words.
>My
specific question is generated by some of the recent very
close up (head shot) images, e.g.Brown
Pelican and Masked Booby. Due to the very limited depth of
field, I presume you focused manually to insure the eyes were
in focus.
AM: That is
incorrect. Most times when doing head shots with the 2X TC
the bird's eye will be somewhere in the middle of the frame,
so I simply use AI Servo.
>How often do you focus
manually?
AM: Rarely, usually
when there is grass or twigs between myself and the subject.
>How often do you use focus
lock and recompose the image?
AM: I sometimes use One
Shot (which locks both focus and exposure), but more commonly
use CF-4-3 which gives me all the benefits of One-Shot and of
AI (artificial intelligence) Servo and allows full time manual
focus override and does not have the main disadvantage of One
Shot (you do not need to keep the shutter depressed. Do note
that CF-4-3 gives you real time exposure (vs "Exposure lock
with One-Shot).
>I know that you dealt with
some of this in your book, but I was interested in your recent
practices and experiences.
AM: See my comments above.
>I may have developed
the bad habit of using AI servo focus too much.
AM: You need to resist the
temptation to use AI Servo if it forces you to become
a compositional slave to the technology.... In other words, if
the active sensor can hold sharp focus on a spot that gives
you the composition that you want, then you are fine using AI
Servo. If not, you need to choose one of the other options:
MF, CF-4-3, or One-Shot.
>I always want to be ready
follow the subject and be ready for that action shot or take
off/landing images of water fowl.
AM: This is where CF-4-3
shines.... The duck is floating there, and you simply touch
the star button to focus on the bird's eye. He stays in the
same spot, you make your images. He floats a bit closer,
refocus with the star button and continue. He begins to take
off, push and hold the star button
with your thumb and you have AI Servo at your command. (When
using CF-4-3, be sure to have AF set on AI Servo (not
One-Shot).
>But I have also noticed
that AI servo mode sometimes has the lens continually hunting
for focus.
AM: Yes, with 2X TCs, and
in low contrast and low light situations, this will happen
more often than not. When doing head shots, I try to start AF
on the bird's eye where there is generally more contrast.
Then I can pan slowly down to the booby's white neck, for
example, and still hold focus (with AI Servo...) In these
situations, I try to use f/11 when possible.
