Canon EOS 20D Service Manual page 39

General Information
12. External Speedlite
12-1 Flash sync contacts:
12-2 Flash auto:
12-3 Flash exposure:
compensation
(5) Illumination duration: Lamp lights during
SW-1 ON. Light level decreases after 1.5
sec. (With the self-timer, it lights 2 sec.
before shutter release.)
(6) Lamp ON indicator: Exposure level display
in viewfinder (dot display disappears for the
first 1.5 sec.)
(7) Shutter-release lock: None (Shutter-release
priority)
Note: With an external EOS-dedicated Speedlite, the red-
eye reduction lamp does not light.
1) Hot shoe: X-sync contacts
• Locking pin hole provided to prevent
Speedlite slippage.
2) Lower side of the body: PC terminal
(1) No polarity.
(2) Both 1) and 2) can be used for
simultaneous firing.
Enabled with the camera's Program AE mode.
(1) With EX-series Speedlites
Works in all shooting modes.
(2) With Canon A-TTL/TTL autoflash external
Speedlites
• Works in manual and stroboscopic modes
and with external flash.
• Does not fire in A-TTL/TTL autoflash
modes.
• Does not work with Speedlites not having
manual and stroboscopic modes.
• Cannot be used with TTL Hot Shoe
Adapter (flash does not fire even in the
Manual/Stroboscopic flash mode).
(3) With non-Canon flash units:
• On-camera unit can synchronize at
1/250 sec. or slower.
• Studio flash can synchronize at 1/60 sec.
or slower (testing recommended).
1) Manual setting
(1) Up to ±2 stops in 1/3- or 1/2-stop
increments.
(2) If flash exposure compensation is set with
both the camera and Speedlite, the
Speedlite's setting will override the
camera's setting.
2) FEB (Flash Exposure Bracketing)
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