This mode is a Canon exclusive and first appeared in the EOS 650 model of 1987. It
is a remarkable and easy way to get the desired depth-of-field effect. All you do
is focus the nearest point you want to be sharp, then do the same for the farthest
point. Then compose the picture and shoot. The EOS-1N selects the best focus point
and aperture value so that everything between the two points appears sharp, as well
as the shutter speed according to the selected aperture for optimum exposure that
is based on the lighting condition and also the film speed used. Evaluative metering
automatically takes over when this mode is being used.