Nikon FM2 - Manual (Page 24)

CONTROLS IN DETAIL —continued
ASA/ISO film speed dial ®
The ASA/ISO scale on the dial has numbered settings for
speeds from ASA/iS012 to 6400. The dots between each pair of
ASA/ISO numbers stand for intermediate settings, such as 64,
80, etc. The iliustration above gives the speeds for ali infer-
mediate settings. ASA/iSO 100 and 400 are indicated in red as
they are used quite often.
ASA/ISO is a numerical rating of the film's sensitivity to a given
amount of light. The higher the number, the greater the sensi­
tivity, and vice versa. The ASA/ISO of your film is indicated on
the cartridge itself. It is also printed on the film carton and on
the data sheet packed inside.
Shutter speed dial ® I exposure
determination
Setting the shutter speed
To set the shutter speed, turn the shutter speed dial to the right
or left until the desired shutter speed number click-stops and is
aligned with the shutter speed index ®. The dial has indications
for B (bulb) and for shutter speeds from 1 to 1/4000 sec. The 250
engraved in red indicates the fastest sync speed for an electronic
flash unit. On B. the shutter curtains ® remain open for as long
as the shutter release button is kept depressed. 1 is for indicat­
ing one second, 2 for 1/2 sec., 60 for 1/60 sec. and so on. One of
the two adjoining numbers, excluding B is two times or 1/2 as
much as the exposure amount of the other number. Note that
shutter speeds between printed numbers (i.e., intermediate
speeds) cannot be used. Since you can always confirm the
shutter speed number inside the viewfinder, you don't have to
see the shutter speed dial as you turn it.
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