Canon EOS 20D Service Manual page 13

General Information
Note that one positive (+) level of the Sharpness setting is equal to twice the
sharpness level of the EOS 10D. This produces more crisp and clear
images.
(3) ISO Speed
• ISO speed setting range
Like the EOS 10D, the EOS 20D's ISO speed range is ISO 100, 200, 400,
800, 1600, and H: 3200. Note that the ISO speed extension is now set with
a Custom Function (C.Fn-08) instead of with the menu.
• ISO auto
The basic ISO auto setting has been changed to ISO 400. This obtains
good image quality and avoids camera shake. The background scene behind
the subject in a flash photo will also look brighter.
(4) Noise reduction
The EOS 20D already obtains better image quality than with the EOS 10D.
To improve image quality of long exposures even more, a Custom Function
for long exposure noise reduction is provided. When C.Fn-02-1 is set, noise
reduction processing will be executed for exposures 1 sec. or longer. Note that
the noise reduction processing will take the same time as the exposure time.
3) Shooting Functions
(1) Autofocus
• AF sensor
The camera has a newly-developed, 9-point AF
sensor (CMOS). The center AF point is a high-
precision, cross-type sensor sensitive to f/2.8 lenses
(vertical line-sensitive at f/2.8, vertical line-sensitive at
f/5.6, and horizontal line-sensitive at f/2.8). The eight
other AF points are sensitive to f/5.6.
Since each AF point is optimized for the imaging
element size, the AF point layout is more inward than
the EOS 10D's. However, the nine AF points
make the subject coverage larger. Also, as shown
in Fig. 007, there are four AF points which are
near a golden section
improve the composing of the shot.
* Golden section: Picture composition deemed to have the
most aesthetic and stable aspect ratio (1:1.1618). When the
picture is divided into nine sections, the four intersections
all have a vertical : horizontal aspect ratio of 1:1.5. If you
use one of the four AF points close to a golden section point
to cover the subject, the composition will look more balanced.
Thanks to the new AF sensor, focusing in low light has improved by 1
stop compared to the EOS 10D. The brightness range required for focusing
is now EV -0.5 to 18.
The AF speed is faster than the EOS 10D's. The predictive AF
point.* They help to
8
Fig. 006 AF sensor
Golden section
point
4.5 3.
7.5 .0
Fig. 007 point positions