Nikon N4004s - Manual (Page 74)

Depth of field: The zone of acceptable sharpness in front of
and behind the subject on which the lens is focused. Depth of
field can be increased by using small apertures (large f-numbers)
or short focal-length lenses, or by taking the picture from farther
away. To reduce depth of field use large apertures (small
f-numbers), long focal-length lenses, and/or near subjects.
DX-code: Film information code printed on the film cartridge.
The N4004S automatically senses the film speed (ISO 25 to
5000) of DX-coded film the instant film is loaded.
EV system; See page 52 and 53.
Balanced fill-flash; Subjects lit from behind or near a window
normally appear too dark in photographs, so it is recommended
you use a flash for fill-in lighting. Although conventional auto­
matic fill-flash system often result in well-exposed subjects, the
background may be washed out of dark. The Decision Master
System of the N4004s performs balanced fill-flash with the
multi-sensor metering, so both subject and background are
correctly exposed, to produce a well-balanced picture.
f-number: Number which indicates brightness of film plane
image. The f-number series is 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22,
32, etc. Changing one step to the next largest number (i.e., from
f11 to f16) decreases image brightness by 1/2; moving to next
lower number doubles brightness.