File:The American annual of photography (1918) (14777971631).jpg

Identifier: americanannualof1918newy (find matches)
Title: The American annual of photography
Year: 1918 (1910s)
Authors:
Subjects: Photography
Publisher: New York : Tennant and Ward
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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l give slower readingsin bright light or with fast plates, for there will be a longerrecord made owing to the light being strong enough to make aregistration even when the shutter is practically closed. Howlong the shutter requires to open—how long it is wide open—and how long it takes to close—all these facts compared withthe total time of operation from start to finish, these thingswill really tell what the shutter does. The Abney and the new Eastman shutter testers are almostthe only ones that show these things—the Eastman being animprovement on the Abney, by getting the intermittent beam ina different way. Either of these machines might be built byanyone who had a machine shop, money, and a technical edu-cation, or in lieu of that sufficient income to buy knowledge,machine work, and training. If you have doubts of your shutter (and if you have not, behappy—know nothing, fear nothing) dont play with it andthese little tricks of testers, get it tested properly and know 148
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w m wu o wo HUO 149 what it does. 1 venture the statement that there is not a manwho has writtenabout falHng balls, pendulums, etc., for testingthat can get results that are within 300 per cent of the actualreadings. The makers of the shutter ought to be able to tell you—theywill if you go after them properly. Do you know that thelargest shutter makers in this country made the statement ayear or so ago, We realize that the markings on our shuttersbear no relation to the actual speeds, but as long as the publicdemands i/ioo on a cheap shutter, and will only buy shuttersthat have it, we must continue to mark them in this way. Assoon as the public realizes that the speed marked on shuttersare only figures that really mean nothing, from the fact thatthey are not within 100% of the truth, we will be glad to sub-stitute a system of marking that will indicate the actual per-formance of the shutter. I had hoped this year to have readya series of plates showing the performances of various we

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