Automatic High-Speed Synchronisation (Hss); Manual Flash Exposure Correction - Metz MECABLITZ 50 AF-1 Manual De Instrucciones

7.3 Automatic high-speed synchronisation (HSS)

Various cameras support automatic high-speed synchronisation (see the
camera's operating instructions). This flash mode makes it possible to use a flash
unit even with shutter speeds that are faster than the flash sync speed.
Interesting results may by achieved in this mode when, for example, a wide
open aperture (e.g., f/2.0) is used to limit the depth of field in portrait shots
taken in very bright ambient light. The flash unit supports TTL high-speed syn-
chronisation in M flash mode.
For physical reasons, however, high-speed synchronisation significantly reduces
the number and the maximum flash range. Be sure to note, therefore, the flash
range on the display of the flash unit. High-speed synchronisation is activated
automatically if a shutter speed faster than the flash sync speed is set on the
camera, whether manually or automatically by the exposure program.
Note that in the case of high speed synchronisation the guide number of
the flash unit also depends on the shutter speed. The faster the shutter
speed, the lower the guide number!
Setting procedure
TTL
TTL
HSS
HSS
17 35
m mm
Zoom
TTL M
„ HSS" or „ HSS" is shown in the display.
High-speed synchronisation can be deleted by repeatedly pressing the „Mode"
button until the „HSS" symbol disappears.
84
• repeatedly press the„Mode" button
TTL M
until„ HSS" or „ HSS" flashes
in the display.
The setting takes effect immediately.
After about 5 seconds the display stops
flashing and the setting is saved automa-
tically.

8 Manual flash exposure correction

The auto flash exposure mode of most cameras is adjusted to a reflection factor
of 25% (the average reflection factor of flash subjects). A dark background that
absorbs much of the light or a highly reflective 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 contrast bet-
ween the subject and background!
Tip:
Dark subject against light background: positive correction factor. Light subject
against dark background: negative correction factor. The setting of the correc-
tion value is carried out on the camera (see camera operating instructions).
No special indicator appears on the flash unit.
Exposure correction by means of alteration of the lens aperture setting is
impossible, since the camera's automatic exposure program regards the
altered aperture setting as the normal working aperture setting. When
setting the correction factor, the distance shown in the display can chan-
ge and be adjusted to the correction factor (depending on the camera
model)!
After the shot, remember to cancel the TTL flash exposure correction in the
camera!
Attention: Strongly reflecting objects in the motif can have a negative impact
on the camera's automatic exposure. The photograph will be
underexposed. Remove reflecting objects or set a positive
correction value.