File:The American annual of photography (1922) (14781307762).jpg

Identifier: americanannualof36newy (find matches)
Title: The American annual of photography
Year: 1922 (1920s)
Authors:
Subjects: Photography
Publisher: New York : Tennant and Ward
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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No. I. i/ioo sec. exposure No. 3. 1/25 sec. exposure. No. 2. 1/50 sec. exposure. No. 4. 1/5 sec. exposure. Figure i. number i and twice as dense as number 2. Number i receivedthe exposure marked i/ioo; number 2 the exposure marked1/50; number 3 exposure 1/25 and number 4 exposure 1/5.One easily notices since number 2 is twice as dense as numberI, and that speed i/ioo was used for i and speed 1/50 for 2,that these speeds are in the ratio of i to 2, i.e., that i/ioois twice as fast as 1/50. The same can be shown and provedwith number 3 which is one-fourth as rapid as number i, andone-half as fast as number 2. Number i compared with num-ber 4 shows that it is twenty times the speed, the density ofwhich was determined by means of a microscope as well as 136
Text Appearing After Image:
A. McFarlin. by the light law of inverse squares which gave the result of19.83 times the intensity of number i. It is hoped by the author that the foregoing proofs will beconvincing evidence to those who have been in doubt as to themisstatements of articles published and issued from time totime. If the readers of the Annual cannot accept the veracityand the proofs as herewith given, they only need to employthe foregoing analysis of the methods of exposures to con-vince themselves and obtain their own proofs. The camera employed for this investigation was procuredfrom the Conley Camera Co. It was fitted with their shutterand a F8 rapid rectilinear lens working at 12^/^ inches. Thenegative was made on Eastman Commercial Orthonon Film.

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