Metering Modes of Digital Camera

Incident Light Meter

(Image courtesy of Graeme Weatherston
at FreeDigitalPhotos.net)

When we take a picture of our subject or a scene, one of the most important aspect that we need to keep in mind is the amount of light present in that particular moment and to calculate that we can use hand-held light meters that can assess how much amount of light is present in a particular situation. So to discuss about that we need to know about two types of Lights Meters, one of them is Incident Light Meter, which calculates the light which is falling on the subject or a scene from all around and the other one is Reflected Light Meter, which calculates the light that gets reflected back after falling on our subject. In this section we are going to discuss about that Reflected Light Meter as, now a days, almost in every digital camera we get built-in light meters which can only measure the amount of light that gets reflected from our subject or from a scene. So, in this way, the concept of Metering Modes comes in to effect in a digital camera, which commonly gives us three different ways to measure the amount of light present in a particular situation & helps us to get the correct exposure and they are Centre - Weighted Metering, Matrix / Evaluative Metering & Spot Metering.

(a) CENTRE - WEIGHTED METERING MODE : When we use Centre - Weighted Metering mode, the camera, statistically, gives more importance or more emphasis or more weight on the middle / central area of the scene or the frame and meters the light from all the cells / zones of the middle / central area of the scene or the frame and then adjusts or averages all the light with the entire scene or the frame. So, in this type of metering mode, we get the middle / central part of the scene to be perfectly exposed & the rest part of the scene to be slightly balanced or averaged out. We can use Centre - Weighted Metering mode in those situations where our subject is in the middle or in the centre of the scene or the frame as well as while we have more light in the background, as in this metering mode, the camera gives more weight to the middle / central area of the scene or the frame and because of that our subject will be perfectly exposed. This type of metering mode is good for portraits as well as for close-up photography.

(b) MATRIX / EVALUATIVE METERING MODE : Matrix / Evaluative Metering mode works slightly similar to Centre - Weighted Metering mode as the camera divides the scene or the frame into different cells / zones & meters the light from all the cells / zones of the scene or the frame and then adjusts or averages all the lights with the entire scene or the frame, but, in this metering mode, it does not give any preference or importance or weight to any particular portion of the scene or the frame. This type of metering mode is not good for those situations where we have lots of light present behind our subject as, due to that bright light in background, our subject may look underexposed, so we can use this type of metering mode for landscape photography where it will collect all the lights from every portion of the scene or the frame and will give an average of all lights to make correct exposure.

(c) SPOT METERING MODE : Spot metering mode works slightly different from the other two types, as in this metering mode the camera meters light only from a small portion of the scene / frame, which may be either at the centre of the scene / frame or at the selected Autofocus (AF) point and ignores the rest of the scene / frame. This type of metering is good for portrait & macro photoraphy as we can give more emphasis or more weight on a specific area of the scene / frame by moving the spot from one Autofocus (AF) point to another.