Canon Speedlite 550EX Instructions Manual page 48

Stroboscopic Flash
48
2
Use the following formula to calculate
the required shutler speed.
Flash count
+
Firing frequency
=
Shutler speed
Example: If
the flash count is 10 and
the liring frequency is 5 Hz, the
shutter speed will have to be at
least 2 sec.
10+5=2
If the flash count display is - - . the flash
will
keep firing until the shu tter speed en ds or
until the maximum number of continuous
ftashes (as indicated in the tabte on page
t 22)
is fired.
3
Focus the subject.
To set th e exposu re settings. see "Manual
Ftash Mode" on page 44.
~
'"I"
56 •
4
Check that the
t
icon is displayed in
the viewfinder, then take the picture.
To prevent overheating and deterioratioo
of
the "ash head, 00
not
use strolxlS<:OPiC nas.h
for more than 10 frames in rapid succession. After 10 frames, allow the 550EX 10 cool for
at least 10 minllles.
.::r.;::: "
-11'-
Stroboscopic flash is most effective with highly reflective subjects in front of a dark
background.
Using a tripod and RBmote Switch are recommended.
Using an external power source
is
.ecommended for sIIoboscopic flash.
Stroboscopic flash cannot be used at a flas.h oulpl.ll of 111 or 112.
buLb can also
be
used wilh stroboscopic flash.