Canon SPEEDLITE 540EZ Service Manual page 25

Part 2: Technical Information
1.2 Built-in Wide Panel
1) Use as a wide-angle diffusion panel
The 540EZ features a built-in wide panel that slides out of the way into the top
cover of the flash head section when not in use. To use the wide panel, the user
simply pulls it out forward all the way and releases it: a built-in spring
automatically swings the panel down to cover the front of the flash head.
In this position, a switch inside the panel slide groove automatically detects that
the wide panel is in use, and the flash automatically zooms to the 28mm position
regardless of whether it is in auto or manual zoom mode. Also, "MZOOM 18" is
displayed in the LCD panel to indicate that the flash illumination angle covers the
area of a super-wide-angle 18mm lens.
However, there is the possibility that this built-in panel could be damaged by
pulling on it with too much force, or by bending it in an unnatural direction. If by
chance the panel breaks, the zoom position will be locked at the 28mm position.
This can be fixed, however, by turning the main switch OFF and then ON again
while simultaneously pressing the flash mode selector button and zoom button. If
this is done, the zoom position will be released and both the auto and manual
zoom mechanisms will continue to function properly. However, the Wide Panel
Segment in the LCD panel will continuously blink to notify the user that the flash
unit needs to be repaired.
2) Use as a catchlight panel for bounce flash photography
The wide panel can also be positioned vertically (at a right angle to the face of the
flash head) by a locking it at the click stop immediately before the panel is pulled
all the way out of its slot.
When the flash is bounced with the panel in this position, part of the light from
the flash will be reflected off the back of the panel and bounced directly at the
subject, creating a small catchlight in the subject's eyes. This catchlight helps add
life to portrait shots.
However, since the strength of the catchlight is quite weak, it is only effective
within a range of 1.5 m from the camera. Also, photographs using this catchlight
method are assumed to be made with the flash in the 90° upward, frontal bounce
position. If the wide panel is left in the catchlight position with the flash head in
the standard position or 7° downward position, the entire display panel will blink
to warn the user.
* The display will start blinking even if the wide panel is withdrawn from its slot
just a few millimeters. If the display starts blinking for no apparent reason, the
user should always check the position of the wide panel first to make sure it is
fully seated.
Figure 2-3 Using the Wide Panel in the Catchlight Position
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