Camera Work: A Photographic Quarterly (1903 (Heft 3))

Air-spaces in Lenses
EVERY SURFACE in a lens will reflect a certain
portion of the light which falls upon it. This
reflected light not only represents a loss of speed,
but it also finds its way into the camera, where
it often causes false images or “ghosts” on the ground glass.
Many lenses consist of three, four, or more glasses
separately mounted in a lens-mount.
Such lenses have numerous reflecting surfaces, but what
is more, the proper adjustment of the glasses one to the
other is apt to suffer, to the detriment of the optical
qualities of the instrument.
The careful buyer will choose a lens without air-
spaces.
COLLINEARS
Have their glasses firmly bound in correct positions
Have no reflecting air-spaces
Have finest definition, depth of focus, brilliancy, covering power, and SPEED


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No. 137 West 23d Street, New York

Camping out in the Mountains
is not only the ideal life, but brings
health and renewed vigor.
GO TO
Scenic Colorado
VIA THE
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THE " COLORADO SHORT LINE,”
VIA THE PUEBLO GATEWAY.
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