3. Flash photography for advanced amateur
and professional photographers
3.1 TTL flash control
This is an auto mode in which the flash exposure is
measured by a sensor inside the camera. This
sensor measures the light that reaches the film
through the lens and is reflected off the film plane.
When the necessary amount of light for a correct
exposure has been obtained, the camera sends a
signal to the flash unit which causes the flash to be
instantly cut off. Any attachments and filters that
may be used on the lens are automatically taken
into account for TTL flash control. TTL flash control
is supported by all operating modes of the camera,
such as full auto mode (green square), intelligent
program P, Av, Tv and M, and the programmed
image control modes.
Various digital cameras do not support "normal"
TTL flash control, but only the E-TTL flash
control mode (see Sections 3.2 and 15.1).
Full auto mode (green square),
intelligent program P, DEP
and programmed image control modes:
(if featured on the camera)
The camera preselects a shutter speed/aperture
combination in conformity with the adjusted
program. The shutter speed selected by the camera
lies between 1/60th sec. and 1/250th sec.
depending on the camera type and the prevailing
ambient light situation (for the synch speed range
please refer to the camera's operating instructions).
Shutter speeds faster than the camera's fastest
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