Specifications
III. NEW AND IMPROVED DESIGN FEATURES 13
New Pr
ecision Matte
F
ocusing Screen
Picture Size Auto Zoom
New High Speed Shutter
Support of EF-S Lenses
up
. A new latch mechanism has been incorporated to reduce the gap around the flash
u
nit. A custom function can disable firing of the built-in flash an external Speedlite or a
non-C
anon flash connected to the PC terminal.
The E
OS 20D features a newly developed Precision Matte
f
ocusing screen that has optimally distributed microlenses.
By controlling the microlens curvature, the overall light
distribution angle is determined. By optimizing the
microlens arrangement, the wide light distribution angle’s
characteristic is controlled as appropriate when a fast lens
is attached. Because of improvements to the shape of the
microlenses, it is easy to distinguish the precise point of focus during manual focusing,
especially with lenses f/2.8 or faster. The new Precision Matte focusing screen has also
reduced viewfinder coloration and increased brightness compared with the EOS 10D.
When the Speedlite 580EX accessory flash unit is used, the flash automatically detects
the EOS 20D’s sensor size. The Picture Size Auto Zoom function controls the zoom and
automatically sets the optimum flash coverage, effectively increasing the guide number
of the flash as well as the number of flashes per charge.
The EOS 20D has a newly developed shutter with a top speed of 1/8000 sec., user-set-
table in 1/3 and 1/2 stop increments (in shutter speed priority AE and manual modes)
and a maximum flash synchronization speed of 1/250 sec. First or second curtain flash
sync is possible. The shutter’s APS-C configuration allows a reduction in the size of the
unit, smaller shutter blades with lower inertial mass, and shorter travel distance.
Stronger magnets are used for each shutter curtain, permitting better control of the
blades. A semiconductor switch replaces the traditional sync contacts, ending scorching
and frictional wear while at the same time increasing the limit for trigger circuit voltage
to 250V. The result of these changes is a more rugged and reliable shutter unit with sub-
s
tantially improved performance.
EF-S Lens compatibility is another way in which Canon
has increased the performance and value of the EOS 20D.
These lenses project a cone of light that covers the APS-C
format; they are optimized for digital imaging. EF-S Lenses
are smaller, lighter and less expensive than those designed
to cover the 35mm format. To accommodate these lenses
in the EOS 20D, the mirror swing-up mechanism moves
the mirror back as it goes up. The mirror itself is smaller compared to the 10D. The EOS
20D shares EF-S compatibility with the EOS Digital Rebel. When purchased with the
zoom lens kit, the EOS 20D comes with the EF-S 18-55 mm f/3.5-5.6 lens. Canon is
EF-S 10-22mm
f/3.5-4.5 USM
EF-
S
17-85mm
f/4-5.6 IS USM
Viewfinder