33
W/O Wide-angle
adapter or Diffuser
(Exposure adjustment)
With Wide-angle
adapter
(Exposure adjustment)
With Diffuser
(Exposure adjustment)
ISO 25 +2 Stop +3.5 Stop +4.5 Stop
ISO 50 +1 Stop +2.5 Stop +3.5 Stop
ISO 100 No change +1.5 Stop +2.5 Stop
ISO 200 –1 Stop +0.5 Stop +1.5 Stop
ISO 400 –2 Stop –0.5 Stop +0.5 Stop
ISO 800 –3 Stop –1.5 Stop –0.5 Stop
The procedure for P mode, including subject program selection, is
the same as that for A or M mode, except that the aperture is set
automatically.
P Mode
• With some cameras, the flash will fire
automatically in P mode. In this case, the
auto lamp will glow and the flash may not
fire if the surrounding conditions are
bright.
• P mode flash program is designed for general subjects, not close-up
or macro subjects. If macro photos are taken, the depth-of field may
be very shallow. If the aperture selected by the camera is outside the
allowable range, the proper exposure can not be obtained (p. 30 - 32).
An additional adjustment must be applied to the previous tables.
Using the diagram at the left, moving one step
vertically is equal to a full-stop change. Moving
one step diagonally, is equal to a half-stop
change.
Example: starting at f/8, if you decrease the
exposure by a full-stop, you get f/11. If you
increase by a half-stop, you get f/6.7.
Example: using an AF 50mm f/2.8 Macro lens,
two twin flash units, no arm, magnification ratio of
1:1, and ISO 100 film. The calculated acceptable
aperture range is f/4 - f/90 (bold type in the table,
page 30). But with ISO 50 film and the diffuser,
using the chart above, you will see that you need
to increase the aperture by +3.5 stops. This
results in a calculated acceptable aperture range
of f/1.2 - f/27. However, because the actual aper-
ture range for this particular lens is f/2.8 - f/32,
the usable range for satisfactorily results would
be f/2.8 - f/27.
When Using Film Other Than ISO 100, Or When Using the
Wide-Angle Adapter or Diffuser
BASIC FLASH MODES
32
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