8. Exposure correction
36
Automatic exposure systems are adjusted to a subject
reflection
factor of 25%, this being the average reflec-
tion factor for subjects
shot with flash. Dark backgro-
unds that absorb a lot of light, or bright backgrounds
that reflect a great deal of light (e.g. backlit scenes),
can result in subject overexposure or underexposure,
as the case may be.
Exposure corrections in automatic flash mode
To compensate the above described effect, exposure
can be corrected by opening or stopping down the
camera’s aperture. If the background is predomi-
nantly bright, the sensor of the flashgun will cut off
the flash too soon with the result that the
subject will
be too dark (underexposed).With a dark background
the
flash is cut off too late so that the subject looks too
bright (overexposed).
Bright background:
Open the camera aperture by 1/2 to 1 f-stop
(e.g. from f/5.6 to f/4)
Dark background:
Close the camera aperture by 1/2 to 1 f-stop
(e.g. from f/8 to f/11)
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