Canon EOS 55 Service Manual page 55

Part 2: Technical Information
e. Ambient light metering in TIL and A-TIL autoflash modes
The flash aperture for TIL and A-TIL autoflash metering described in d above is
set to suit the ambient light as metered by the respective exposure mode (evalua-
tive [no automatic exposure compensation], partial, or centeiweighted averaging
metering).
2) Exposure Control
1. AE control
S1
S2
S3
S4
Fig. 2-12 Off-the-f'llm metering pattern
Except for Sports mode (whose program has been changed) and Depth-of-field AE (eye-
control compatible), AE control is basically the same as with the EOS 5/A2E.
a. Sports mode
To freeze moving subjects, this mode sets a fast shutter speed with Shutter-prior-
ity AE and continuous focus tracking. It sets the camera to Al Servo AF, auto-
matic focusing point selection or Eye-Controlled Autofocus, continuous shooting,
evaluative metering, and high-speed program AE. The built-in flash is disabled.
The PH-1 mode is based on using an EF 50mm f/1.8 lens. Starting at maximum
aperture, only the shutter speed shifts (faster speeds) until +2.5 EV steps beyond
the speed where the camera-shake warning is given. The program then shifts
both the shutter speed and aperture at a rate of 1:2 (1\r:Av) stops.
When other lenses are used, the program line is based on the lens' focal length
and maximum aperture to attain a fast shutter speed and depth of field under
bright conditions. From the point +2.5 EV steps beyond the speed where the
camera-shake warning is given, the program line shoots upward as both shutter
speed and aperture shift.
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