KEY METERING MODES

ZONE METERING

1

Often called Evaluative metering on Canon cameras or Matrix on Nikons, this is essentially a zone metering system that divides up a large portion of the frame into segments and uses algorithms to deliver a well-exposed shot in a wide range of scenarios. Some of these systems can put a bias around your autofocus point to make sure this part of the image doesn’t clip. This is less useful when you want to intentionally under- or overexpose the picture for creative purposes.

CENTRE-WEIGHTED

2

This mode works a similar way to zone-based metering modes, as the whole frame is scanned and taken into account; but here the exposure is heavily biased to correctly expose for the tones in the central area of your shot, to make sure these don’t become over- or underexposed. The diameter of the central area on a Nikon D500, for example, measures 8mm by default, or about 6% of the frame, but can be changed to 6mm, 10mm or 13mm to give more or less weight to the central area.

SPOT METERING

3

Spot metering systems reduce the area taken into consideration for exposure down to a small point. This is usually just 1-4% of the centre of the frame, though some cameras let you set a spot point elsewhere on the screen or use the active AF point to spot-meter from. Some cameras also have a Partial metering mode which covers a larger area of the frame (6-9%): this produces more consistent results than Spot, where moving your framing even slightly can produce wildly different exposures.