An item in the Custom Settings menu “b Exposure/metering” group. Selecting “On” has the following effects when the camera is in exposure mode M:

• If the user changes shutter speed, the camera will automatically adjust aperture to maintain exposure at the value currently selected by the user

• If the user changes aperture, the camera will automatically adjust shutter speed to maintain exposure at the value currently selected by the user

In existing cameras, the user had to adjust both shutter speed and aperture manually to maintain the same exposure. Selecting “On” would, for example, allow the user to quickly change shutter speed for different amounts of motion blur when photographing a race car as it went through a corner.

This function works as follows:

1) The user selects “On” for “Custom Settings > b Exposure/metering > b7 Manual EV lock”.

2) The user selects exposure mode M (manual).

3) The user manually chooses shutter speed and aperture with reference to the exposure indicator.

4) The users locks exposure (as determined by the combination of shutter speed and aperture) at this value by pressing the button to which autoexposure lock has been assigned.

5) The user adjusts either shutter speed or aperture.

6) The camera automatically adjusts the remaining parameter (aperture or shutter speed).