Complete the vocabulary of exposure measurement.
A standard grey card reflects ______ per cent of the light falling on it. The metering method that is indifferent to the subject's reflectance is ______ metering. A flash's ______ number is the product of the distance and the correct f-number at a stated film speed. Illuminance falls as one over the distance ______, which is the inverse-square law.
Word bank: eighteen · incident · guide · squared · twelve · reflected
Hints
- The first blank is the reflectance the whole system is built around.
- The last blank is what makes the law inverse-square rather than merely inverse.
Show the answer
A standard grey card reflects eighteen per cent of the light falling on it. The metering method that is indifferent to the subject's reflectance is incident metering. A flash's guide number is the product of the distance and the correct f-number at a stated film speed. Illuminance falls as one over the distance squared, which is the inverse-square law.
The four terms cover both halves of the lesson: what the meter assumes, the method that avoids the assumption, the shorthand for flash output, and the geometry that makes distance matter so much more than intuition suggests.
Practise Exposure and Metering
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More questions on Exposure and Metering
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