Samsung gx-1 User Manual (en)

Setting the Exposure
Linking AF Point and AE During Multi-Segmented Metering
In [Link AF Point and AE] (p.100) of the [       Custom Setting] menu, you can link the exposure and
focus point during multi-segment metering. The default setting is [Off].
Exposure is set separately from focus point.
Exposure is set in accordance with focus point.
ƈ Metering is weighted at the center of the screen. 
Use this metering when you want to compensate the exposure
by experience, instead of leaving it to the camera. 
The illustration shows that sensitivity increases as the pattern
height increases (center). This mode does not automatically
compensate for backlit scenes.
Using the Center-Weighted Metering
ƈ With spot metering, brightness is measured only within a limited
area at the center of the screen as shown in the illustration. 
You can use this in combination with the AE lock (p.141)
when the subject is extremely small and proper exposure is
difficult to obtain.
Using the Spot Metering