The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Exposure
(5) Distance. Mr. Watkins, in his little pamphlet " Notes on Exposure," says on this subject: '* It may be taken as a general rule that, except when photographing near objects (less than twenty-four times the focus of the lens distant), or, on the other hand, extreme distances in landscape, no variation need be made for differences in distance. When a very near object is photographed, the camera has to be racked out, and the ex-posure increases in proportion to the square of the increased focus of the lens. When the subject is more than twenty-four times the focus of the lens distant (18 feet for a 9-in. lens), this variation is too minute to be taken into account, and if the air were perfectly clear - as it is sometimes among the Swiss peaks - all objects beyond that distance would require the same ex-
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