Same Exposure For New Aperture - Canon EOS-1DX Instruction Manual

Same exposure for new aperture

If the <a> mode (manual exposure shooting) is set and the ISO speed is
set manually (other than Auto ISO), the maximum aperture's f/number may
change to a high number (smaller aperture) or a low number if you perform
any of the following: 1. Change the lens, 2. Attach or detach an Extender, or
3. Use a zoom lens whose maximum aperture f/number changes. If you
then shoot at the exposure setting as is, the image will be underexposed or
overexposed by the amount the maximum aperture f/number changes.
However, by changing the ISO speed or shutter speed (Tv) automatically,
you can obtain the same exposure that would be obtained before you
performed 1, 2, or 3.
OFF: Disable
Automatic changes in settings to maintain the specified exposure will not
be applied. The ISO speed, shutter speed, and aperture already set will
take effect in shooting. If you perform 1, 2, or 3 and the maximum
aperture f/number changes, adjust the ISO speed and shutter speed
before you shoot.
ISO: ISO speed
If you perform 1, 2, or 3, the ISO speed will automatically increase or
decrease by the amount that the maximum aperture f/number changes.
The same exposure that would be obtained before you performed 1, 2,
or 3 is obtained.
Tv: Shutter speed
If you perform 1, 2, or 3, the shutter speed will automatically increase or
decrease by the amount that the maximum aperture f/number changes.
The same exposure that would be obtained before you performed 1, 2,
or 3 is obtained.
3 Custom Function Settings
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