Nikon D5100 Reference Manual page 26

Choose an aperture
(mode A; 0 64).
Choose an
aperture
(mode M;
X
0 65).
Set exposure
compensation
(mode P, S, or A;
0 70).
Choose a flash mode (0 51).
Adjust flash compensation (mode P, S, A, or M; 0 72).
P, S, A, or M
8
Mode A
E button
Mode M
E button
Mode P, S, or A
M button
+
M button E button
Command dial
+
Command dial
+
Command dial
+
Command dial
+
Command dial
Information display
Information display
Information display
Information display
Information display