Canon EOS 6D Instruction Manual page 312

3 Custom Function SettingsN
C.Fn III -2 Focusing screen
If you change the focusing screen, change this setting to match the focusing
screen so that correct exposures are obtained.
0: Eg-A II
1: Eg-D
2: Eg-S
About focusing screen characteristics
Eg-A II: Standard Precision Matte
Standard focusing screen that comes with the camera. It provides
both adequate viewfinder brightness and manual focusing ease.
Eg-D : Precision Matte with Grid
The focusing screen has grid lines. It helps
to keep the picture horizontal or vertical.
Eg-S : Super Precision Matte
Makes it easier to see the perfect focus
than with the Eg-A II. Convenient if you
often focus manually.
Although the Eg-A focusing screen can be installed in this camera, it will
not obtain the correct exposure.
Maximum Lens Aperture with Super Precision Matte Eg-S
Optimum for lenses whose maximum aperture is f/2.8 or larger.
If you use a lens whose maximum aperture is smaller than f/2.8, the
viewfinder will look darker than with the Eg-A II focusing screen.
This setting will be retained even if you select [8: Clear all Custom
Func. (C.Fn)].
Since this camera's standard focusing screen is Eg-A II, C.Fn III -2-0 is
set upon factory shipment.
For details on changing the focusing screen, refer to the focusing
screen's instruction manual. If the focusing screen does not come down
together with the holder, tilt the camera toward you.
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