B3: Center-Weighted Area; B4: Fine Tune Optimal Exposure - Nikon D90 User Manual

b3: Center-Weighted Area

When calculating exposure, center-weighted metering
assigns the greatest weight to a circle in the center of the
frame. The diameter (φ ) of this circle can be set to 6, 8, or
10 mm. This option is available in P, S, A, and M modes only.

b4: Fine Tune Optimal Exposure

Use this option (available in all shooting modes) to fine-tune the exposure value
selected by the camera. Exposure can be fine tuned separately for each metering
method by from +1 to –1 EV in steps of
D
Fine-Tuning Exposure
Exposure can be fine-tuned separately for each Custom Settings bank and is not affected by
two-button resets. Note that as the exposure compensation (E) icon is not displayed, the only
way to determine how much exposure has been altered is to view the amount in the fine-
tuning menu. Exposure compensation (pg. 90) is preferred in most situations.
L
178
1
/ EV.
6
Option
M φ 6 mm
L φ 8 mm (default)
N φ 10 mm