Canon PowerShot Pro 90 IS User Guide

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Using an Externally Mounted Flash (Optional)

You can make your flash photography even clearer and more natural appearing
with the use of a separately sold externally mounted flash. The camera’s auto
exposure function will operate with a Canon Speedlite 220EX, 380EX, 420EX or
550EX. Non-Canon brand flashes may not fire. Please check the manual for your
flash. (Certain functions noted in the manuals for the Speedlite 220EX, 380EX,
420EX and 550EX cannot be performed when mounted on this camera. Please
read this guide before using one of these flashes on the camera.)

Attach the flash to the camera’s hot
shoe.

Turn the external flash on and turn the
camera’s main dial to 

.

Turn the mode dial to a mode other
than 

 or 

.

Speedlite 220EX, 380EX, 420EX or 550EX
• The flash will automatically adjust its output

in the 

,  ,  ,  ,  ,  ,  , 

 and 

modes. The maximum flash synchro shutter
speed is 1/250 second.

• The flash will fire at full strength in   mode.

Manually set the shutter speed and aperture to
appropriate settings in this mode. At shutter
speeds slower than 1/250 second (maximum
flash synchro shutter speed) determine the
appropriate aperture value setting from the flash’s
guide number and the distance to the subject.
You are also recommended to set the white
balance to the 

 setting.

Speedlite 420EX Mounted
on the Hot Shoe