Nikon D90 User Manual page 328

The Command Dials
In P, S, A, and M modes, the following settings can be
adjusted by rotating the command dials (pg. 24).
~~
Fl'
's'
~_-,_=
~.~
,
~ ~AF-A
J
--- L:::
' J
[S :: -:J
NORM ~ A
\~
.
Choos~a
p
combination of
aperture and shutter
speed
S
Choose a shutter
speed
A
Choose an aperture
M
Choose an aperture
Choose a shutter
speed
30