Speedlite Technology - Canon EOS Rebel T2i Brochure

SPEEDLITE TECHNOLOGY

Integral to the EOS System, Canon Speedlites
are the ideal flash source for EOS SLR cameras.
They are technologically advanced to provide
perfect exposure and illumination with just
about any subj ect, yet operation is remarkably
simple. Whether you're an amateur or an
expert, Canon Speedlites make it easy to
obtain professional results.
Sophisticated Flash Control Modes
E-TTL—In E-TTL (Evaluative Through-The-Lens) flash
exposure control mode, meter readings are taken
through the lens, but not off the focal plane. Using
a preflash fired after the shutter button has been
fully depressed—but before the camera's reflex
mirror goes up—E-TTL uses the camera's Evaluative
metering sensor to compare the ambient light
values with the light reflected from the subject
by the preflash. The camera then calculates and
stores the flash output required for optimum
exposure of the main subject (as identified by
the AF point) and the background. E-TTL requires
the use of EX-series dedicated Speedlites
such as the 580EX II, 430EX II, 320EX, 270EX II,
220EX, MT-24EX, or MR-14EX in combination
with a compatible camera.
E-TTL II—Available on Canon's EOS digital SLR
cameras, E-TTL II incorporates distance information
from compatible EF lenses (see page 30 for
details) for more versatile flash exposure control.
E-TTL II minimizes underexposure that can occur
with straight reflections by ignoring sensor areas
that report abnormally high levels. This feature
is useful when shooting a subject with a highly
reflective object in the background, or if the
subject itself is highly reflective. In addition,
because distance information is used in calcu-
lating the flash output level, E-TTL II prevents
overexposure when photographers lock focus
and recompose.
SLR Compatibility
Camera Model E-TTL E-TTL II A-TTL / TTL
EOS-1Ds Mark III No Yes † Not Possible
EOS-1D Mark IV No Yes † Not Possible
EOS 5D Mark II No Yes † Not Possible
EOS 7D No Yes † Not Possible
EOS 60D No Yes † Not Possible
EOS 50D No Yes † Not Possible
EOS 40D No Yes † Not Possible
reading of flash and ambient lighting data for up
EOS 30D No Yes † Not Possible
EOS Rebel T3i / T3 / T2i / T1i / XSi / XS No Yes † Not Possible to 16 seconds. This provides enough time to not
EOS Digital Rebel XTi / XT No Yes † Not Possible
EOS-1v / EOS-3 Yes No 4-point / 3-zone only recompose the shot, but also alter the ambient
EOS ELAN 7 Yes Yes 4-point / 3-zone
ne
light exposure for maximum creative control. FE
EOS Rebel T2 / T2 Date No Yes Not Possible
EOS Rebel K2 / K2 Date Yes No 4-point / 3-zone
Lock is extremely useful when you wish to recom-
Speedlite Compatibility
E-TTL / E-TTL II A-TTL TTL Manual pose after focus lock or to place the main subject
580EX II Yes No Yes Yes
†† †††
in a part of the frame not covered by one of the
430EX II Yes No No Yes
††
320EX Yes No No Yes
††
focusing points. It can also eliminate potential
270EX II Yes No No Yes
††
270EX II Yes No No No
††
exposure errors caused by unwanted reflections
220EX Yes No Yes No
†† †††
MR-14EX Yes No Yes Yes
†† †††
from surfaces like windows or mirrors.
MT-24EX Yes No Yes Yes
†† †††
† Not Linked to AF point. †† Requires EOS body that supports E-TTL and E-TTL
II respectively. ††† Defaults to TTL in all conditions except direct flash in the
camera's Program mode.
Adjusting Ambient Exposure in FE Lock**—After
preflashing the subject with the FE Lock button,
For example, with the EOS-1D Mark IV, the ambient ambient exposure can be adjusted by turning the
light is first measured using the camera's 63-zone Quick Control Dial. The ambient exposure level is
metering when the shutter button is pressed. displayed on the exposure level scale in the
Next, a preflash is fired and the metering sensor viewfinder and on the external LCD panel.
takes readings. The ambient and preflash readings
FP Mode***
are compared. The metering areas having small
differences are selected as the main flash exposure FP (focal-plane) flash, or High-speed Sync, enables
areas. Areas with large discrepancies between E-TTL and E-TTL II compatible cameras equipped with
ambient and preflash readings are excluded or an EX-series Speedlite to synchronize flash at shutter
down-weighted because they are assumed to speeds faster than the camera's normal maximum
contain a highly reflective subject, or the subject sync speed. Even in bright daylight, for example,
is not in that part of the frame—an assumption a fast lens can be used at a wide aperture to reduce
validated by distance information. The algorithm depth-of-field and emphasize the subject. FP flash
thus helps avoid chronic underexposure problems can be combined with E-TTL, E-TTL II, or FE Lock,
in such situations. These readings are weighted, and is available in all AE modes plus Manual.
averaged, and compared with the ambient light
Flash Exposure Compensation****
reading and the main flash output is then set
and stored in memory. This setting adjusts flash output without changing
the shutter speed or aperture. It's a particularly
The E-TTL II, in effect, captures the subject as a effective way to fine-tune the balance between
"plane" and not as a "point." As a result, EOS foreground and background exposure for fill flash
SLR cameras can help deliver consistent flash
exposures even if the subject contains various
colors and levels of reflection. The camera also
allows the user to select an averaged metering
pattern through custom function settings.
TTL*—TTL (Through-The-Lens) is the standard
flash exposure control mode used by the built-in
flash units that come with some 35mm EOS film
cameras. Unlike E-TTL or E-TTL II, TTL reads flash
illumination reflected from the film during the
exposure. When the camera is set to Program AE
mode, TTL flash sets an aperture based on the
ambient light level.
Flash Exposure Lock (FE Lock)
FE Lock adds Auto Exposure lock and Spot metering
functions when shooting with EX-series Speedlites
and E-TTL compatible EOS cameras. The EX-series
Speedlite's preflash fires when the camera's AE
Lock button is depressed, storing a Spot meter Taken with MT-24EX and EOS-1v HS
*ATTL and TTL are not compatible with digital SLR cameras. See lens chart for a listing of lenses that supply distance information. **Ambient exposure cannot be adjusted when the camera is set to Bulb mode or in
low-light situations when the camera is set to Program AE or A-DEP. ***Unlike conventional electronic flash, FP flash output (guide number) decreases as shutter speed increases above normal X-sync speed. ****Flash
exposure compensation can be set with most current Speedlites, and it can also be set with all current EOS cameras other than the EOS Rebel series and EOS Digital Rebel.
SPEEDLITES
High-Speed Sync — EF 135mm f/2.0L USM lens •f/2 •1/750 sec.
shots, but it can also be used to compensate for
extremely bright or dark tones in the subject.
Second-Curtain Sync
Instead of firing the instant the shutter opens,
Second-Curtain Sync fires the flash at the end of
the exposure, allowing streaks of light to flow
naturally behind a moving subject. This creative
flash mode is most effective with slower shutter
speeds and subjects with light sources, such as
the headlights of a moving car.
Stroboscopic Flash
Stroboscopic flash is a series of flashes fired in
rapid succession during a single exposure. With
stroboscopic flash, multiple images of a moving
subject appear in the photograph. Using this
mode, you can analyze a golf swing or record the
shattering of a windowpane. (Available with
Speedlite 580EX II, Macro Ring Lite MR-14EX
and Macro Twin Lite MT-24EX, the built-in flash
of the EOS 7D).
LED Light
In a first for Canon
Speedlite flashes, the
320EX features a
bright, built-in LED light
for illumination when
shooting video or for
use as a modelling light. With fully charged
AA batteries, the LED light can last for up to
four hours of continuous use.
Flash Release Function
Select Speedlite models include a convenient
feature that enables photographers to release
the camera shutter from the remote flash wire-
lessly with a 2-second delay. With EOS DSLR
cameras that provide a master function with
remote reception mode, this feature makes it
possible to reposition the flash with complete
freedom – even out of the camera's line-of-sight
and at some distance from the camera.
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