Metz MECABLITZ 58 AF-1 N digital Mode D'emploi page 107

10.5 Manual flash exposure corrections
The auto flash exposure mode of the flash unit, as of most cameras, is adju-
sted to a reflection factor of 25% (the average reflection factor of flash sub-
jects). A dark background that absorbs much of the light or a highly reflecti-
ve bright background (backlit shots, for example) may result in, respectively,
underexposure or overexposure of the subject.
To offset these effects, the flash exposure can be adjusted manually for the
shot with a correction value. The extent of the correction depends on the con-
trast between subject and background.
In TTL and automatic flash modes, manual flash exposure correction factors
of from -3 EV (f-stops) to +3 EV (f-stops) can be adjusted on the flash unit in
one-third increments.
Many cameras have a setting element for exposure corrections that can also
be used in TTL flash mode. Please refer to the information in the camera's
operating instructions.
Dark subject in front of a bright background:
Positive correction value (approximately +1 to +2 f-stops EV).
Bright subject in front of a dark background:
Negative correction value (approximately -1 to -2 f-stops EV).
When a correction value is set, the flash range indicated on the flash unit
display may change as it adjusts to the correction value (depending on the
type of camera). For adjustments, see 6.4.
Manual flash exposure correction is possible in TTL flash mode only if
the camera supports this function (consult the camera's operating
instructions). If the camera does not support this function, the adjusted
correction value will have no effect. For some camera models, the
manual flash exposure corrections must be adjusted on the camera. If
this is the case, no correction value will appear on the flash unit
display.
11. Flash readiness indication
When the flash capacitor is charged, the flash readiness symbol
up on the flash unit, indicating that the flash is ready to fire. This means that
flash light can be used for the next shot. Flash readiness is also transmitted to
the camera and indicated accordingly in the camera's viewfinder (see 15).
If a shot is taken before the flash readiness indicator appears in the camera's
viewfinder, then the flash unit will not be triggered and, if the camera has
already switched to flash sync speed (see 12), the shot may have the wrong
exposure.
The multi-zone AF measuring flash
can be activated by AF cameras only when flash readiness is indica-
ted (see 20).
12. Automatic flash sync speed control
Depending on the camera model and camera mode, the shutter speed is
switched to flash sync speed when flash readiness is reached (see the
camera's operating instructions).
Shutter speeds cannot be set faster than the flash sync speed, or they are
switched automatically to the flash sync speed. Various cameras have a sync
speed range, for example from 1/30 sec. to 1/125 sec (see the camera's
operating instructions). The sync speed set by the camera depends on the
camera mode, the ambient light, and the focal length of the lens used.
Shutter speeds slower than the flash sync speed can be set according to the
camera mode and the selected flash synchronisation (see also the camera's
operating instructions and 18).
If a camera with a between-the-lens shutter (see the camera's opera-
ting instructions) or FP high-speed synchronisation (see 18.4) is used,
flash sync speed is not controlled automatically. As a result, the flash
can be used at all shutter speeds. If you need the full light output of
the flash unit, you should not select a shutter speed that is any faster
than 1/125 sec.
lights
integrated into the flash unit
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