Within the camera is light meter – a reflected light meter. It allows for measurement of reflected light within a scene. The metering system chosen will effect how this reflective light is measured.
The exercise asks for consideration of how the camera’s light meter works, enabling consideration of its benefits to the photographer and its limits.
The following images were taken in ‘program mode’ to view the camera’s automatic adjustments based on its metering of light to zero.
Black Fabric photographed in program mode, and screen shot of levels pertaining to image.
Grey Card photographed in program mode, and screen shot of levels pertaining to image.
White Paper photographed in program mode, and screen shot of levels pertaining to image.
The above images demonstrate that if the camera is set to ‘program mode’ and allowed to control exposure automatically it will, by virtue of its reflective metering and its programmed automatic modes expose white, when photographed as the predominance of a scene and black when photographed as the predominance of a scene – as grey. The camera has been searching to meter to what it’s programmed to meter for – and that is the midtone. Its programming cannot perceive a vastly black or vastly white scene, similarly to the black fabric and the white paper.
This ‘flaw’ with reflective metering is why taking full control of the camera’s exposure, in manual mode, disconnecting any relational shift between aperture, shutter and ISO allows for an exposure true to what the eye perceives to be recorded.
Below are images taken of the same black fabric, grey card and white paper using the camera’s manual mode.
Black fabric in manual mode and screen shot of levels pertaining to the image
Grey card in manual mode and screen shot of levels pertaining to the image
White Paper in manual mode and screen shot of levels pertaining to the image
It can be seen in the above image of the white paper, the black and white data mapped in the levels chart and additionally the colour data mapped in the histogram that the white paper has recorded as a midtone when recorded to an exposure value of zero in manual mode. Here a standard difficulty found photographing predominantly white scenes, even in manual mode, such as snow and also white animals is illustrated graphically.
The capture of the white paper was repeated with an exposure adjustment of plus two stops. This exposure adjustment, visible on the reflective metering guide within the viewfinder, allows for the white paper to be rendered as white and to show on the levels mapping close to the 255 value of absolute white.
White paper in manual mode, plus two stops of exposure and levels pertaining to the image.
The exercise shows not only the ‘flaw’ of reflective metering but begins to demonstrate some advantage of manual mode.
Manual mode gives greater control to the photographer as removing dependence from programmed modes reduces the need to tolerate the programmed capacities of the camera’s metering. In moving into manual mode we get to see the camera’s reflective metering read-out and still we don’t have to expose to zero, just as this image (used in Assignment 1) wasn’t exposed to zero, deliberately, so as to demonstrate the intention and creative choices selected to communicate the intention.
Manual mode, though considered by some a challenge and being slightly slower due to the disconnection of the elements of the exposure triangle provides greater possibilities for creative control. Semi automated modes such as aperture priority and shutter priority can have flexibility, especially with the use of exposure compensation, though if a dramatically different choice is to be executed it would be necessary to move from aperture priority to shutter or vice versa. Or to move into manual mode.