Exposure latitude

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As exposure latitude is called the tolerance range of a photosensitive layer in which they without serious loss of quality one over - or underexposure permits.

The exposure latitude of a film is also the buffer zone against incorrect exposures . The exposure latitude also indicates by how many f-stops a subject can be overexposed or underexposed without restricting the highlighting or shadow areas.

functionality

From a sensitometric point of view, the exposure latitude of a photographic layer corresponds to the difference between the exposure range ∆ lg H and the exposure interval ∆ lg E. If the exposure interval is greater than the exposure range, it can no longer be completely reproduced on the light-sensitive layer.

practice

Depending on the type of incorrect exposure, if the exposure latitude is exceeded or not reached, shadows , lights or both are reproduced too light or too dark. One then speaks of the shadows "drowning" or the lights "eating up".

This incorrect exposure can be eliminated either by reducing the scope of the object or by increasing the scope of exposure of the layer, so this corresponds to a flattening of the gradation . Such corrections are possible to a limited extent when making enlargements in the photo laboratory or when processing images electronically .

Slide films have a much smaller exposure latitude than negative films ; they must therefore be exposed much more precisely .

Some light meters like the Minolta Flashmeter VI can show the exposure latitude along with a measured value on the display.

Information on the exposure latitude and the gradation curve of a film can be found in the data sheets of the respective manufacturer.

See also: sensitometry , gradation curve , exposure series

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