Exposure & Metering
60 terms · page 2 of 3
F-number
The ratio of a lens's focal length to the diameter of its entrance pupil, written f/2.8, f/8 and so on, and the standard way of stating…
Exposure & MeteringFilter Factor
The exposure increase, in stops or as a multiplier, needed to compensate for the light a filter absorbs.
Exposure & MeteringFlicker Reduction
A camera function that times the shutter release to the peak of a pulsing artificial light source, preventing exposure and colour shifts…
Exposure & MeteringGrey Card
A physical card of known neutral 18 per cent reflectance, held in the subject's light to give both a reliable exposure reading and a white…
Exposure & MeteringHandheld Light Meter
A separate instrument for measuring incident, reflected or flash light independently of the camera.
Exposure & MeteringHighlight Alert
A playback warning, often called blinkies, that flashes any area of the image where the brightest tones have clipped.
Exposure & MeteringHighlight-weighted Metering
A metering pattern that biases exposure toward protecting the brightest area of the frame from clipping.
Exposure & MeteringHistogram
A graph of how many pixels in an image fall at each brightness level, from black on the left to white on the right.
Exposure & MeteringIlluminance
The amount of light arriving on a surface per unit area, measured in lux, independent of what that surface does with it.
Exposure & MeteringIncident-light Metering
Measuring the light falling onto a subject rather than the light reflecting off it, using a handheld meter with a white diffusing dome.
Exposure & MeteringISO
The standardised measure of how strongly a camera amplifies the signal it captures, determining image brightness for a given exposure.
Exposure & MeteringLooney 11 Rule
The lunar counterpart to Sunny 16: a full moon is correctly exposed at f/11 with a shutter speed of one over the ISO.
Exposure & MeteringLuminance
The brightness of a surface as seen from a given direction, measured in candela per square metre.
Exposure & MeteringManual Mode
A mode, marked M, in which the photographer sets aperture and shutter speed directly and the camera only advises.
Exposure & MeteringMeter Calibration Constant
The factor K in the exposure equation that ties a measured luminance to a recommended camera setting.
Exposure & MeteringMetering Mode
The pattern a camera uses to sample scene brightness when calculating an automatic exposure.
Exposure & MeteringMiddle Grey
The reference tone, reflecting about 18 per cent of the light that strikes it, that every reflected-light meter is calibrated to reproduce.
Exposure & MeteringNative ISO
Any ISO value produced by real analogue gain in the sensor's readout circuitry, as opposed to numbers created by brightening the file in…
Exposure & MeteringOverexposure
An exposure that records more light than the sensor can hold, driving the brightest tones to pure white with no recoverable detail.
Exposure & MeteringPartial Metering
A metering pattern reading roughly the central eight to fifteen per cent of the frame — broader than spot, narrower than centre-weighted.
Exposure & MeteringProgram Mode
An automatic mode, marked P, in which the camera selects both aperture and shutter speed while leaving other controls to the photographer.
Exposure & MeteringReciprocal Rule
A handholding guideline stating that the slowest safe shutter speed is roughly one over the focal length in use.
Exposure & MeteringReciprocity Law
The principle that exposure depends only on the product of light intensity and time, so halving one and doubling the other leaves the…
Exposure & MeteringReflected-light Metering
Measuring the light bouncing off a subject toward the camera, which is what every built-in camera meter does.