Canon Speedlite 540EZ Manual page 19

0 Cover the subject with the
viewfinder's AF frame and
press the shutter button
halfway.
• When the shutter button is
pressed halfway, the camera
focuses the subject and the
flash coupling distance indicator
bar and aperture value are dis¬
played in the flash unit's LCD
panel.
7 Check the shooting distance indicated on lens' distance scale.
3 Check the coupling distance indicator bar in the LCD panel.
If there is a difference between the shooting distance (indicated on
the lens' distance scale) and the LCD panel's coupling distance indi¬
cator bar, adjust the aperture until the coupling distance indicator
matches the shooting distance.
• The coupling distance indicator bar can also be adjusted by changing the
flash output power level.
• if there is a large difference between the shooting distance and the coupling
distance display, change the flash output power level and refocus the subject,
then adjust the aperture until the distance indicated on the coupling distance
display is the same as the shooting distance.
• For more precise exposure control, use a commercially-available handheld
flash meter.
0 Make sure the shutter speed
and aperture value displayed
in the viewfinder are not blink¬
ing and that the flash charge
indicator
$
is lit, then take
the picture.
3. Stroboscopic Flash
The 540EZ's stroboscopic flash function rapidly fires the flash several
times in succession during a single exposure to record the flowing motion
of a subject.
The stroboscopic firing frequency (measured in number of flash bursts
per second, or "Hz") can be set within in a range of 1 Hz ~ 100 Hz. The
frequency is set in 1 Hz increments between 1 Hz and 20 Hz, in 5 Hz
increments between 20 Hz and 50 Hz, and in 10 Hz increments between
50 Hz and 100 Hz. Up to 100 continuous bursts is possible during a sin¬
gle exposure, but this limit differs depending on the firing frequency and
output power level used. For details, refer to the "Maximum No. of
Continuous Flash Bursts" chart on page 21.
• Use fresh batteries when using
stroboscopic flash.
• Stroboscopic flash is not possible
at the 1/1 and 1/2 power settings.
• Due to the slow shutter speeds
required with stroboscopic flash,
we recommend using a tripod
and the Remote Switch 60T3.
• We recommend using an external
power supply when performing
stroboscopic flash photography.
If the stroboscopic flash has been fired 15 times continuously, allow the Speedlite
to rest for 15 minutes to prevent the flash head from overheating. Overheating
can cause the flash head to breakdown.
19