7.2 Preflash TTL and ADI metering
Preflash TTL and ADI metering are digital TTL
flash operating modes and refined versions
of the TTL flash operation found in analogue
cameras. When taking a shot, an almost
imperceptible measurement preflash is
triggered by the camera prior to the actual
exposure process. The reflected light of the
measurement preflash is evaluated by the
camera. Depending on the result of the
evaluation, the subsequent flash exposure is
adapted by the camera to suit the given shot
situation (see camera operating instructions
for further details). In the case of ADI
metering, additional distance data from the
lens is incorporated into the flash exposure
process. The selection and/or setting of the
preflash TTL and ADI metering operating
modes are carried out on the camera
(see camera operating instructions).
The flash unit must be set to the
operating mode.
TTL
flash
7.3 Manual flash mode
In the manual flash mode M , the flash unit
emits the full uncontrolled amount of light if
no partial light output has been selected.
The specific photographic situation can be
taken into account by adjusting the aperture
setting or by selecting a suitable manual
partial light setting.
The setting area ranges from P 1/1 to P
M
1/128 in
mode and P1/1 - P1/32 in
M HSS
mode. The display shows the distance
at which the subject is correctly lit (see 5.2).
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