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Lens Performance Magnified 240X
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H E n e w P h o t o g r a p h i c Lens T e s t i n g P r o jector, d e s i g n e d a n d built by B&L engineers, s h o w s visually o n a l a r g e screen the exact quality of i m a g e p r o d u c e d by t h e lens. T o test t h e A n i m a r 8 m m m o t i o n picture camera lens, a Bureau of S t a n d a r d s test chart, covering the diagonal of a n 8 m m frame, is projected, by the lens b e i n g tested. T h e result is an i m a g e on the screen at a magnification of 2 4 0 d i a m e t e r s . . . approximately τΛ i n c h magnified to 4% feet! T h e lens is focused to give the best p o s s i b l e definition at the center of t h e field. For this setting, resolution is read at t h e center a n d m a r g i n s of the field. At the same time, variations in focus from the nor mal value a r e r e a d o n a dial gauge. Parfocality of t h e s e lenses is c o n t r o l l e d within a tolerance of ± „0Ol". Exceptionally fast, simple, and accu 486
rate, this m e t h o d insures uniformly h i g h quality lens performance. Another method i n progressive o p t i c a l engi neering for testing performance of lenses—an important factor in establishing Amexican-made B&L p h o t o g r a p h i c lenses as the ultimate in quality a m o n g p h o t o g r a p h e r s everywhere.
BAUSCH & LOMB
M
OPTICAL COMPANY
:A
ROCHESTER 2 , Ν. Υ.
Cooperating tvith Men of Science sirzce 1853
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