Canon EOS-1D X Firmware Update Addresses f/8 & Red AF Points in AI Servo Ť Canon Rumors
The new firmware allows cross-type autofocusing with the center AF point even when the maximum aperture of a Canon EF lens/extender combination becomes as small as f/8. Ideal for wildlife photographers and others who often use EF super-telephoto lenses with extenders, this new feature greatly expands the range of EF lens/extender combinations that support autofocus when used with the EOS-1D X.
If AF point expansion is selected with an f/8 maximum aperture lens/extender combination, the four AF points surrounding the center point will act as AF Assist points. This option effectively expands the size of the AF detection area to enhance autofocus performance with subjects that are small in the frame and difficult to track, such as small animals and birds in flight. AF points above and below the center will be sensitive to vertical contrast, while points to the left and right will be sensitive to horizontal contrast.