>>3485687...The user can decide whether shutter or aperture priority
might be appropriate under different circumstances, such
as moving subject matter, due to depth-of-field require-
ments, low light levels or long-focus lenses. So there is
a choice of ‘normal’, ‘action’ and ‘depth’ AE programs.
Additionally, the insertion of an alternative lens of different
focal length may automatically select one of three shutter-
biased program modes usually referred to as ‘wide’, ‘stan-
dard’ and ‘tele’, with the turning point of the program line
on the EV graph at the point where the minimum hand-
held shutter speed may be used. The slope of the program
line may increase progressively from ‘wide’ to ‘tele’. A zoom
lens may alter the program selected continuously as focal
length is altered.
In any programmed AE mode the aperture value is
selected by the camera in increments that maybe as small as
0.1EV. When used with a metering-pattern system capable
of some analysis of tonal distribution of the subject matter,
programmed exposure modes are capable of producing
a high proportion of acceptably exposed, sharp results.
>not so dumb, for measly P, eh? But that's nothing compared to what digital auto modes do.>too dumb for internet:Accurate determination of camera exposure, especially by
in-camera TTL AE systems, is limited by variations in
subject luminance ratio and non-typical subject tone
distributions, which necessitate their recognition and
classification by the user. Examples of such images include
those containing large areas with very light tones or very
dark tones; in these cases auto-exposure will often result in
incorrect results, as the camera will be basing the exposure
on an average of the scene, assuming that it should be
a mid-grey. The use of spot metering, small-area and
various weighted integrated readings can help, with intel-
ligent use...
