Switching the Flash Coverage
The flash head can be extended or retracted manually to match the lens
focal length. As the focal length of EF lenses and EF-S lenses differs,
extend or retract the flash head while referring to the table below (the
flash head position in relationship to the lens focal length).
Normal position
Guide number 24/79 (ISO 100 in m/ft.)
Flash Head Position and Lens Focal Length
Flash Head Position
Lens Focal
Length
Flash head position
Normal Position
EF-S Lens
15mm or longer
EF Lens
24mm or longer
When using an EF-S lens with a focal
length of 32mm or longer or an EF
lens with a focal length of 50mm or
longer, extend the flash head for
greater flash output and longer flash
range.
When the flash head is extended, the
<TELE> lamp on the Speedlite lights
or blinks.
When the <TELE> lamp blinks, retract
the flash head to its normal position. If
you take a picture while the <TELE>
lamp is blinking, the periphery of the
picture may appear dark.
Extended position
Guide number 32/105 (ISO 100 in m/ft.)
Extended Position
32mm or longer
50mm or longer
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