The Dictionary Of Photography

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

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Pigment Process                              Pinhole Photography
interested in learning full particulars as to this remarkable application of photography should refer to Chapter VI. of Tissandier's "History and Handbook of Photography," trans-lated by J. Thomson, London, 1876. Sampson Low & Co.
Pigment Process. See Carbon Process, Artigue's Pro-cess, Mariotype, Gum-Bichromate, and Ozotype.
Pinhole Photography. Of late years the possibility of taking passable negatives without the use of an ordinary camera and lens has become an established fact. For this purpose any rectangular box which is absolutely light-tight will do. In one end insert a very thin plate of metal in which a minute hole has been made with the point of a needle, and at the other end place the sensitive plate, keeping it in its place by means of a clip or other simple arrangement. A prolonged exposure is required, about twenty or thirty times the ordinary one for any given subject. No focussing is required, as the image is always fairly sharp, no matter what distance the plate is from the hole. The larger the plate the wider the angle, and the greater the dis-tance the larger the image. Mr. Alfred Watkins has calculated out a table as a guide to the best results, and suggests that, as ordinary sewing needles are made ,to standard sizes, they should be used to punch the holes in the metal plate or card.
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