Canon EOS-1DS MARK III Instruction Manual page 82

Program Line
The following program line applies when the camera is in Program AE
< P > mode.
5 10 11 12 13 14 t5 16 17 18 19 20 21 22 23
W [22 ] >
I-i 5.0
2.8
F-]........... 2
_ 1.4
_ t.o
30 15 2 4 8 15 30 60 1252505001000200040008000
Shutter speed
Understanding the Program Line
The lower horizontal axis represents the shutter speed, and the right-hand
vertical axis represents the aperture.
The combinations of shutter speed and aperture automatically determined by
Program AE are shown as lines with respect to the subject brightness
(Exposure Value) levels on the left and top edges of the graph.
Using an EF50mm ft1.4 USM lens with a subject brightness of EV12, the point
where the diagonal line from EV12 (on the top edge) intersects the Program AE
line represents the corresponding shutter speed (1/320 sec0 and aperture
(f/3.5) that the program sets automatically. The diagonal arrowed lines at the
upper left indicate the metering range for each ISO speeds.
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