Viewfinder and Exposure Meter

An image of a camera viewfinder

The exposure meter should always have the line in the center to start with, this should give you the correct exposure or close to it.

The camera meter has a variety of exposure modes including:
Spot meter – takes the exposure from a small area of the lens 10% or less
Centre Weighted – takes the reading from the centre of the lens
Matrix metering – automatic metering that takes readings from lots of areas of the viewfinder and averages them out.