How E-TTL II Works
When you press the shutter button, EX
Speedlites fire a low power metering flash a split
second before exposure. The Evaluative pattern is used to
measure both ambient light and flash. The
camera analyzes all Evaluative metering zones before and
after the preflash. E-TTL II measures flash
data across a flat plane rather than a point,
unlike E-TTL and TTL, which were strongly biased to the active
AF point. Any any rate, these changes resulted
in consistently excellent 5D flash exposures, something I
appreciate after using a 10D for 3 years.
Speedlite
430EX • Released simultaneously with the EOS
5D, the 430EX is the "kit" flash for this
body. Here's a review
of the 430EX.
E-TTL II can use distance
data to tweak exposure. However,
distance data is not necessary for excellent exposures. In fact,
it is not used for bounce, wireless
and multiple Speedlites because the camera has no way of determining
flash to subject distance. Moreover, some older lenses are unable
to transmit distance data.
Automatic Fill-in Flash
In bright light, above EV 10, the Speedlite provides
automatic fill-in flash in Full Auto and P modes. In dim light,
EV 10 and below, flash is the main light in Full Auto and P modes
(the background may be dark). Av, Tv and M modes deliver automatic
fill-in flash in any light, even at night (slow sync mode). Slow
sync results in a natural balance between ambient light and flash.
You may need a tripod due to the resulting slow shutter speeds.
I find the understated look of Speedlite fill
flash perfectly balanced. Some
shooters prefer more "pop" and may add flash exposure compensation
to taste.
Balanced Fill-in Flash
• EOS 5D, EF 24-105 4L IS USM, 220EX • Balanced fill flash in Av mode (Main Street Station, Las Vegas)
With
auto white balance, the
5D/430EX combo tends to produce a slightly warm color
temperature in tungsten or mixed
light. I was initially surprised as
fill flash normally looks bluish-white compared to ambient
light.
The 430EX and 580EX communicate
color
temperature information with E-TTL II bodies, so I
suspect this is a feature and not a bug. I
like the
color
temperature blend but subjects
may have less pop than
if rendered bluish-white. Main light
flash has the normal
bluish-white electronic
flash
look. Of course you can tweak WB to taste prior to RAW conversion. Incidentally,
the Flash white balance setting in DDP too warm for
my taste (Daylight looks better).
Agashi
at the Venetian • EOS
5D, EF 24-105 4L IS USM & 430EX
Speedlite. I shot wide open at F4 in
Av mode, allowing the 430EX Speedlite to render auto fill-in
flash, blending subject and background light. The flash head was manually
zoomed to limit coverage to subject only
(didn't
want to
illuminate
the fence).
Custom function CF14.1
sets flash metering to "Averaging" and disables auto
fill-in flash reduction, yielding main light illumination for
every exposure if not compensated manually. Flash performance
is similar to auto thyristor units of yesteryear, e.g., Vivitar
283. CF14.1 is ideal if you prefer
to control fill-in flash
with flash exposure compensation (FEC). Plus, CF14.1 may solve
flash "underexposure"
problems some claim (I haven't experienced any!). Of course,
flash illumination is
a matter of expectations and taste. To some fill-in flash is
underexposure and they expect and desire the deer-in-headlights
look (DIHL) of auto
thyristor units. I prefer the understated
look of fill-in flash mixed with ambient so I'm usually happy
with default settings.
Strangely, in dim light, the 5D
and other recent A-Type bodies reduce ambient exposure in slow
sync mode (e.g., Av or Tv modes at night). In light dimmer than
EV10, ambient exposure is progressively reduced, reaching -1
one stop by EV 7 or so (varies according to ISO). The EOS A2,
Elan, Elan II and IX don't exhibit this odd behavior. Maybe Canon
considers ambient light underexposure a feature because it makes
flash lit subjects stand out? However, I'd rather have no exposure
reduction. The photographer should make the choice themselves.
If you'd like to know more about this phenomena, visit the folks
at the EOS Documentation Project. They even gave it a name: Flash
Negative Evaluative Exposure Compensation or NEVEC.
FE Lock & Flash Exposure Compensation
FE Lock is great for off-center subjects
or troublesome highlights that fool the meter. FE Lock works
like a spot or partial meter for flash. First, place the center
AF sensor on your subject and press the AE/FE Lock button (*).
The Speedlite fires a low power preflash. Exposure is determined
by the reflectance of the subject in the metering circle, so
be careful what you aim at. Use a medium toned area for best
results. Finally, you have 16 seconds to recompose and shoot.
The flash will expose the subject correctly even with usually
light or dark backgrounds or an off-center subject.
If you intend to use FE Lock on an
unusually light or dark object, e.g., a white wedding dress,
apply appropriate flash exposure compensation first (it doesn't
work after FE Lock): subtract 1 to 2 stops of flash compensation
for dark subjects and add 1 to 2 stops of flash exposure compensation
for light subjects. Why? Spot or partial meters are calibrated
to read 18% gray tones. No matter where you point, the camera
expects a medium tone (18% gray) and gives you the correct meter
reading for this result. However, flash exposure compensation
is easy to set:
1. You must be in P, Av, Tv, or M
for flash exposure compensation to work.
2. Press the flash exposure compensation
button (camera top).
3. Turn QCD until you get the amount
of flash exposure compensation you desire (the -2 to +2 scale
is on the LCD). Some Speedlites, e.g., 430EX and 580EX, have
dedicated controls which override onboard
camera controls.
AF
Assist
Speedlites also cure
the camera's lack of an AF assist
light. Under dim conditions, Speedlites
emit a deep red focus pattern. So far I've
only tested the 430EX and ST-E2 with the 5D. Both provide full
coverage of all nine AF points at 20 to 30 feet, depending on
conditions.
Wireless
Flash
Like
all E-TTL capable bodies, the 5D may be used with multiple wireless
Speedlites. You need
both master and slave units, e.g., 420EX (slave) or 430EX (slave)
and a 550 EX (master), 580EX (master) or ST-E2 (master). Read
my review of the ST-E2
Speedlite Transmitter if you'd
like to learn more about wireless flash.
Lens
for Ebay • EOS
5D, EF 50 1.4L USM, 430EX Speedlite bounced onto reflector & triggered
by the ST-E2 Speedlite Transmitter, ISO 200, F16 in Av Mode.
Speedlites
for the 5D
The
dedicated "kit" flash for the 5D is the 430EX.
I
found the
5D and 430EX the best body and flash combo I
have ever used. I rarely override flash settings as
it gets it right nearly everytime. Nevertheless, any EX series
Speedlite will work with the 5D, although not all
E-TTL features will be available. If you want a basic
pocket sized unit, sort of a missing popup flash, the 220EX is
the ticket.
The 420EX
Speedlite is discontinued but is a good choice if you
want a full sized unit on a budget.
It has few controls but advanced features such as 2nd curtain sync and Exposure Compensation may be accessed
through onboard camera controls.
If you'd like to
learn more about Canon flash, check out NK Guy's excellent
treatise, Flash
Photography with Canon EOS Cameras.
