What Is Metering On A Camera

In photography, the metering mode refers to the way in which a camera determines exposure. Cameras generally allow the user to select between spot, center-weighted average, or multi-zone metering modes. The different metering modes let the user to select the most appropriate one for use in a variety of lighting conditions. In complex light situations professional photographers tend to switch to transmission mode, rather than depending on a setting determined by the photographic camera.

Examples of metering modes [edit]

Digital metering feedback

Spot metering [edit]

With spot metering, the camera will measure out simply a very pocket-sized area of the scene (ane–5% of the viewfinder area). By default this is the heart of the scene. The user can select a dissimilar off-centre spot or recompose by moving the camera after metering. Sure models support a mode which allows averaging of multiple spot meter readings, and some support metering of highlight and shadow areas.

Spot metering is not influenced past other areas in the frame. It is unremarkably used to shoot very high dissimilarity scenes. For example, in a backlit situation a rising lord's day may exist behind a person whose face up will be much darker than the bright halo around the torso and hairline. Spot metering allows the camera to measure the light reflected from the person's face and expose properly for that, instead of adjusting exposure for the much brighter lite around the hairline. With the face properly exposed, the area around the back and hairline will become over-exposed. In many cases spot metering will over or underexpose a portion of the scene, then that the point of involvement will exist correctly exposed.

Another example of the use of spot metering is photographing the moon. Other metering methods will increase overall exposure in an attempt to lighten the dark heaven area, resulting in overexposure of the moon. Spot metering gives correct exposure of the moon and underexposes the rest of the scene which was nighttime already, so the depression exposure is not noticeable. Spot metering may also be used for theatre photography, where brightly lit actors appear in a darkened auditorium. Spot metering is a method upon which the Zone Arrangement depends.

Center-weighted average metering [edit]

In this system, the meter concentrates on the key threescore–eighty% of the scene. The remainder is and then "feathered" out towards the edges. This mode of exposure is less influenced by peripheral areas of the scene and is therefore well suited for photographs with subjects or objects of involvement in the central office of the image. Some cameras allow the user to adjust the weight/balance of the primal portion to the peripheral 1. If the photographic camera allows a user to motility the focus bespeak off the image center, metering will occur around the new focus location. Although promoted as a feature, center-weighted metering was originally a consequence of the meter reading from the focusing screen of SLR cameras. Light scatter from the focusing screen and proximity of the meter cell caused less sensitivity at the edges.

Average metering [edit]

In this metering mode, the camera uses light data from the entire scene and creates an average for the final exposure setting, giving no weighting to whatsoever detail portion of the metered area. In some situations, such equally a snowy mural, this mode volition result in underexposure by 2 f-stops or more, because the metering system attempts to darken an excessively brilliant scene.

Partial (selective) metering [edit]

This manner meters a larger area than spot metering (around 10–xv% of the entire frame), and is mostly used when very bright or very dark areas on the edges of the frame would otherwise disproportionately influence the metering. As in spot metering, some cameras can use variable points for readings or use a fixed bespeak in the centre of the viewfinder.

Multi-zone metering [edit]

Honeycomb Metering on a Dynax 5D. The AF betoken was set to the heart of the toy; the camera has been able to produce a skilful exposure, by not being fooled past the strong dorsum lighting of the out of focus areas.

This mode is also chosen matrix, evaluative, honeycomb, segment metering, or esp (electro selective pattern) metering on some cameras. This metering mode was outset introduced past the Nikon FA and was termed Automatic Multi-Pattern metering. On a number of cameras this is the default or standard setting. The camera measures the low-cal intensity in several points in the scene and then combines the results to detect the setting for the best exposure. The method of calculation tin can be different from camera to camera. The actual number of zones used varies widely, from several to over a thousand. The design concept behind multi-zone is to reduce the demand to use exposure bounty.^[1]

Many manufacturers go along their exact calculation methods confidential as proprietary information. A number of factors are taken into consideration, including: autofocus indicate, distance to subject, areas in or out of focus, colours/hues of the scene, and backlighting. Multi-zone tends to bias its exposure towards the autofocus point, thus ensuring that the point of interest has been exposed for properly. A database of thousands of exposures may be pre-stored in the camera, and the processor can utilize that information to determine what is being photographed.^[two]

Some cameras let the option of locking exposure when autofocus is achieved. In other cameras the AF point is not used for exposure calculation, and in such cases it is common for metering to default to a cardinal bespeak in the viewfinder, using a blueprint based on that area. In that location is considerable variation among different manufacturers how multi-zone metering is implemented–even in the model range of the same brand–and how much priority is given to the AF bespeak itself. Some "Scene" modes, such every bit dusk, sports and night exposures also often affect the calculations of this metering pattern.

Highlight-weighted metering [edit]

Clipping is reduced by using a high resolution metering sensor and analyzing each area for done-out ("blown") highlights or underexposed shadows.^[three] Although in that location are some similarities with multi-zone, matrix, or evaluative metering, this way uses a high-resolution sensor for detailed detection and gives more weight to reduce clipping.^[4]

References [edit]

^ Catechism engineering description for evaluative metering. Archived May 22, 2007, at the Wayback Machine
^ "Exposure Metering". Nikon Corporation. Archived from the original on 2010-04-28.
^ "Nikon D810 Announcement". PhotographyLife.
^ "Offset Look Review: Nikon D810". Amateur Photographer.