Metz MECABLITZ 45 CL-4 Mode D'emploi page 42

system as soon as the ambient light level is no longer sufficient for automa-
tic focusing. The autofocus ermitter emits a striped pattern. If an SCA 300
autofocus adapter is used, only the autofocus measuring beam built into
the adapter is activated.
• Program auto flash mode
Some cameras merge in the „Program" mode the ambient light with the
light emitted by the flashgun. The camera automatically adjusts a shutter
speed/aperture combination, and controls the flash in TTL mode.
Operation of the flash/camera combination thus becomes very simple.
when using an SCA 3002 adapter all SCA 300 functions can be perfor-
med, plus:
• TTL fill-in flash control
Some system cameras offer TTL fill-in flash control in addition to the stan-
dard TTL flash control mode. This operating mode is used for daylight
exposures to brighten up dense shadows and for shots against the light
(contre-jour). The camera's, in conjunction with internal sensor measure-
ment within the camera, ensures that the correct amount of flash light is
emitted to achieve a balanced exposure. The camera automatically per-
k
forms the flash exposure correction that is necessary for fill-in flash shots.
• TTL flash exposure correction
There are certain photographic situations where the camera's internal sen-
sor can be deceived. This can be particularly the case with a dark subject
in front of a bright background (the subject is overexposed). To overcome
this problem in such a photographic situation an still achieve a correct epo-
sure in the TTL flash mode, some cameras can influence the flash power of
the flashgun. All elements of an exposure are influenced by normal expo-
sure corrections with the help of aperture or shutter-speed settings, change
of film speed or by the + correction on the camera. However, the overall
exposure can be retained with the help of the special exposure correction
function so that only the darker sections are brightened up by the flash.
Further details on this mode are given in the respective operating instruc-
tions for the adapter and camera.
• A-TTL flash control
42
(only with Canon SCA 3101/3102 Adapter)
A pre-flash is fired to supply the camera with additional distance data and
metered exposure values. As a result of these data the camera's electronics
automatically adjusts the required shutter-speed/aperture-setting combina-
tion. The camera controls the amount of light emitted by the flashgun for
this purpose.
• Pre-flash to avoid red eyes
(only with Sigma SCA 3601 Adapter)
The red-eye effect is a physical phenomenon. It arises whenever a person,
against a relatively dark background, is looking straight into the camera
when the flash on the camera is fired. The light from the flash is reflected
by the blood vessels in the retina through the pupils an is recorded on the
film as red spots in the eyes-hence red eyes. The red-eye reduction facility
offers significant advantages in this respect. When this function ist adjusted
on the mecablitz a successsion of three visible weak flashes is fired before
the shutter is tripped, and prior to the measuring beam for the multi-sensor
(it possible with flash unit resp. camera); the pre-flashes are immediately
followed by the main flash. The light of these pre-flashes induces the pupils
to close, thereby substantially reducing the red-eye effect. This function is
available with all exposure programs. For further details please refer to the
operating instructions of the camera.