Canon EOS-1DS MARK III Instruction Manual page 57

Custom Function Settings
0: Disable
1: Enable
Improves the highlight detail. The dynamic range is expanded from the
standard 18% gray to bright Mghtights. The gradation between the grays
and highlights becomes smoother.
With setting i: the Settable ISO Speed range will be 200 :i 600. AJs0: the ISO speed
displayed on the top LCD panel and in the viewfinder, will have the "O"displayed as a
smaller character such as fi2ed'; When the image's sh0Qting info (p.! !7) is
displayed, the IS© speed's !!0'!wi[J aJsobe dispJayed as a smaiUercharacter.
0: Eva_uative flash metering
Fully automatic flash photography for all conditions, from low light to
daylight fill-flash.
1: Average flash metering
The flash is averaged for the entire area covered by the flash. Since
automatic flash exposure compensation will not be executed, you may
have to set it yourself depending on the scene. This also applies if you
use FE lock.
0: 1st-curtain synchronization
1: 2ndocurtain synchronization
The flash fires right before the shutter closes. When a slow shutter speed is
set, you can capture a light trail foJlowing the subject.
This Custom Function can be used to obtain 2nd-curtain sync effects even
with EXoseries SpeedJites which do not have this feature, if the EXoseries
Speedlite has this feature, it wilJ override this Custom Function's setting.
@ With setting i a preflash wili be fired foi flash metering c0ntr0J righi after
you press the shutter button comp!etely. Remember that the mai n flas h w!! !
then fire right before the shutter closes.
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