[ebookman]

可否解釋一下以上三種測光模式

我明白各種的不同

我想問問
重點測光是否只可作中央的主體曝光?
不能作鏡頭其他點以作測光?

[dclkwok]

one weak point of canon's owner's manual is not detail enough. you may refer to Nikon's one,, if your friend got one. Simply speaking,

權衡式測光

your camera divide the picture you would like to take into several divisions for calculating optium aperture and shutter speed for exposure.

中央重點平衡測光

similar to above but weighting at centre objects.

重點測光

weighting at centre objects only, e.g. taking picture for people

select appropriate method for right exposure.

[jasonksh]

From dpreview.com:

Center-Weighted Average Metering
Probably the most common metering method implemented in nearly every digital camera and the default for those digital cameras which don't offer metering mode selection. This method averages the exposure of the entire frame but gives extra weight to the center.

Spot (Partial) Metering
Spot Metering allows you to meter for the subject directly in the center of the frame (or on some cameras at the selected AF point), this is normally a small circle just 10% the area of the whole frame, the exposure of the rest of the frame is ignored. Useful for brightly backlit or macro shots.

Matrix or Evaluative Metering
This is probably the most complex metering mode, and each manufacturers exact detail on how they implement matrix metering is closely guarded. Sufficient to say that the scene is split up into a matrix of metering zones (between 30 and 200), each of which are evaluated individually, the overall exposure is based on an algorithm specific to that camera. Matrix metering often offers the best exposure possible.