Reference Guide

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ZOH Sta nda rd image interval
for the in-focus condition
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Image Interval
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New Cross-Type BASIS Sensor.
But there are other contributing
factors to EOS-l's superior AF
performance. The AF Sensor itself
has been modified to provide a
second set of sensing elements,
aligned vertically to form a new
Cross-Type array. This CT - TTL-SIR
(Cross-Type, Through-The-Lens,
Secondary - Image-Registration)
system increases the reliability
and speed of the focusing process
in several ways.
Difficult AF subjects become much
easier to detect since both
horizontal . and vertical lines in
the subject are evaluated when
using lenses with maximum apertures
of f/2 . 8 or faster. Low-Light
performance is extended to EV - 1
because of a special circuit
amplifier which improves signal
clarity by a factor of 10.
12
Plane 01 locus ( Iilm Pla neli
l
LV- B ASIS
Secondary image formation lens
Both vertical and horizontal
sensors are read simultaneously. If
either the vertical or horizontal
information is the only available
data, the focusing process moves on
to the next step of driving the
lens. If, on the other hand, both
sets of sensors provide usable
information, EOS-l is intelligent
enough to select which signal is
more reliable based on a comparison
of greater subject size.
Choice of One Shot or AI Servo
Continuous Focusing.
Much more important than it sounds,
this choice, especially when
combined with the increased framing
rate of the Power Booster El
becomes a valuable creative tool.
In One Shot focusing, the camera
locks focus immediately and holds
the initial setting until you let
up on the shutter release. In this