Speedlite Transmitter Review
Wireless and Happy!
The ST-E2 Speedlite
Transmitter is a wireless controller and trigger for EX series Speedlites. The wireless possibilities are
exciting, especially getting the main flash
off the camera. The ST-E2 also sports a
powerful near infrared AF assist light, a
welcome feature for EOS cameras lacking an AF
Frary Guitar Duo | EOS 20D, EF 17-40 4L USM, 430EX/420EX & ST-E2
ST-E2 Speedlite Transmitter on
EOS Elan 7E
should be used with an E-TTL capable camera
and Speedlite for best results. Older A-TTL cameras, e.g., EOS A2 or 1N, only can only use the ST-E2 in manual
The ST-E2 is
small and light, tipping the scales at 100 g (3.5 oz) and
62H x 51H x 80D mm. The power source, a 2CR5
lithium battery, is extremely light,
especially compared to AA batteries.
feel a difference in weight with the ST-E2
attached to a DSLR. Although light,
it appears well built, perhaps a little more
beefy than the 430EX II Speedlite.
MT-70 Metronome | Canon EOS 10D, EF
50 2.5 Compact Macro, Manfrotto 190,
420EX triggered by the ST-E2 and
bounced off a white panel
The ST-E2 is
optimized to work with the 45-sensor AF
arrays of the EOS 3, 1V and 1D series
cameras. Indeed, the AF assist light works
perfectly in ECF, manual AF selection
and auto AF selection modes with my
EOS 3. If you shoot in low available light
conditions and have difficulty locking AF,
the ST-E2 is an excellent fix (at least
within the AF assist beam range). The deep
red AF light is discreet—I can
hardly see it—and won't offend most
I tested the ST-E2 on a 5D in a dark room.
It projects the entire AF pattern while in auto select AF mode
and covers all points. However, when I select individual
AF points, it does not project anything for the upper and lower
center points of the diamond. It works perfectly
for the other 7 AF points, including the far left and
right points (will snag AF on a plain white wall). The
results are exactly the same on my 20D, 40D, XTi and 5D MKII.
an excellent job with the Elan 7E and 10D,
but isn't a perfect fit. The AF assist light
of the ST-E2 projects a pattern of horizontal
lines that cover all 7 AF sensors of the Elan
7 and 10D in auto selection mode.
Unfortunately, only the 5 horizontal sensors
work with the AF assist beam. Why?
The ST-E2 doesn't emit the AF assist light
when the top or bottom AF sensors are
selected via ECF or manual selection. Perhaps
this is because the top and bottom sensors of
the Elan 7 and 10D are mainly sensitive to
vertical lines and, thus, are unable to
achieve AF with a horizontal pattern.
However, I don't miss the top and bottom AF
sensors much (too many years of using an A2
and EOS 1N).
light, I often prefer to AF with the center
cross sensor and leave the others off along
with ECF. However, I tested the ST-E2 with
all 45 AF sensors of the EOS 3 and 7 sensors
of the Elan 7E and 10D. In automatic sensor
selection mode, I found it locked on to
anything in total darkness, even a blank
white wall while using a slow zoom. However,
the outer edges of the horizontal line
pattern are fainter than the middle, leading
to focus difficulties with outer AF sensors
after 20 feet. However, I can often snag
focus with the center cross sensor with
objects over forty feet away. The official AF
assist range is 34 feet for the center area.
There were no
differences in AF speed with the 420EX or
ST-E2 attached to my Elan 7E or 10D. However,
with the same lens (EF 28-105 USM), center AF
sensors selected, my A2 and its built-in AF
assist light is slightly faster at focusing.
The Elan 7E adjusts AF (rocks back and forth
slightly) before locking. The A2 just flies
to it and stays.
On the Elan
7E, you may set CF7-3 to disable flash but
retain AF assist. On the 10D, set CF5-3 to
disable flash but retain AF assist.
Unfortunately, the EOS 3, 5D and 5D MK II lack this custom
walked around with the Elan 7E/ST-E2 in my
right hand and the 420EX flash in my left
hand and shot party portraits. I could quickly
control the angle and height of the flash for
more pleasing results than shoe mounting the
flash. Also, bouncing off a ceiling or wall
was much faster than using the normal tilt
and swivel features of the 420EX. Of course,
there were no red eye problems whatsoever.
For small group shots, I often placed the
420EX 5 or 6 feet to one side (on a stand or
held by a volunteer), enough for good
modeling and a little bounce off a white wall
for fill. I've used similar techniques with
the Off Shoe Cord 2 many times, but the ST-E2
is more convenient and flexible. By the way,
the ST-E2 works great with the Off Shoe Cord
2 if you need to trigger Speedlites behind
your shooting position.
While in slave mode,
Speedlites omit near infrared pulses, making
them easy to find in the dark!
I shot many
small objects with the EOS 3, Elan 7E, 10D,
40D, 5D, 5D MK II, ST-E2 and 420EX/430EX flash with excellent results.
For the BG-E4 image below, I placed the
430EX on the floor 5 feet to the right, set
the grip on white surface and used
a white reflector on the left for fill. I
used no compensation and let the Evaluative
flash meter do its thing.
Canon BG-E4 Battery Grip | EOS 5D (M mode), EF
24-105 4L IS USM, ST-E2 Speedlite Transmitter, 430EX
Speedlite bounced into white panel and
Manfrotto 190 Tripod.
was impressed at how easy it was to set
ratios with the ST-E2: enable ratio control
and scroll to the desired ratio. Ratios from
8:1 to 1:1 to 1:8 are available for the main
and fill Speedlites. The modeling flash,
activated with the DOF button on most EOS models, was helpful in selecting the
correct ratio. It's easy to burn through a set
of flash batteries playing with it!
No Second Curtain Sync
When the 420EX/430EX is shoe mounted
or used with the Off Shoe Cord 2, second
curtain sync is operational. Unfortunately,
second curtain sync is disabled in slave mode
(wireless mode) with the ST-E2 and EX Speedlites.
trigger beam is wide and strong, so line of
sight isn't usually necessary indoors. The ST-E2 can
trigger the 420EX Speedlite even when facing
the the opposite direction (it reflects off
nearby surfaces). However, outdoors, or without reflective surfaces, line-of-sight is needed. In the image below, the
420EX was pointed at a reflector on the right
side of the ST-E2.
Elan | Photo taken with EOS 5D/24-105 4L IS USM, ST-E2, & 430EX Speedlite bounced into white reflector.
If you need a wireless
multiple-flash system for field work, the
ST-E2 is an essential tool along with a 430EX
or 580EX Speedlite or two. The precision and
flexibility of the system beats the tar out
of wires and optical slaves. Plus, you also
get a wonderful AF assist light to
ST-E2 Speedlite Transmitter on
EOS Elan 7E
Clip-on Speedlite transmitter with direct
Cameras: Type A EOS cameras (E- TTL,
autoflash); Type B EOS cameras (Manual flash)
Ratio Control: For A:B ratio: 1:8 to 8:1,
in half- step increments or 13 steps
Speed Sync (FP flash): Enabled with
high-speed sync mode
Operation Confirmation: With test
transmission button. *Slave A fires followed
by slave B at 1/64 output.
Exposure Confirmation: Before flash fires
during FE lock Adequate flash exposure
indicated by the flash exposure level icon
lit in the viewfinder. Insufficient flash
exposure indicated by the flash exposure
level icon blinking in the viewfinder. After
flash fires, ST-E2's flash confirmation lamp
lights in green for 3 seconds.
slave SE mode cancellation: Cancels when
the test transmission button or FE lock
button is pressed to turn on the slave unit.
Transmission: Infrared pulse
Range: Indoors: 12-15 meters/39.4 - 49.2
ft; Outdoors: 8-10/ 26.2-32.8 ft
Coverage: ±40° horizontal and
Life: Approx. 1,500 transmissions (At
room temperature and with a new set of
Beam: Fully compatible with EOS 1V, 3 and
1D's 45-point Area AF and 28mm and longer
lens focal lengths. Compatible only with the
5 horizontal AF sensors of the Elan
Beam Effective Range: Approx. 0,6 to 10
m/2.0 to 16.5 ft along the periphery (in
Feature: While the power switch is set to
I or HOLD, the transmission turns off
automatically after about 90 seconds of
Source: 2CR2 lithium (6V) battery x 1
62 (W) x 51 (H) x 80 (D) mm/2,4 (W) x 3,1 (D)
100 g/ 3.5 oz (excluding battery)
| Updated 10/13/2014
2002-2017 by Peter Kun Frary | All Rights