WHAT IS CAMERA LENS?
The camera lens is an invention that attempts to duplicate the operation of the
human eye. Just like the eye, the lens sees an image, focuses it, and
transmits its colors, sharpness, and brightness through the camera to
the photographic film, which, like our memory, records the image for
processing and future use.
MANUFACTURING PROCESS
Grinding and polishing lens elements
Optical glass is supplied to lens manufacturers by specialized vendors. The
glass elements are shaped to concave or convex forms by a curve generator
machine that is a first-step grinder. To reach the specifications for its shape, a
lens goes through a sequence of processes in which it is ground by polishing
particles in water. The polishing particles become smaller in each step as the
lens is refined. Curve generation and subsequent grinding vary in speed
depending on the frailty, softness, and oxidation properties of the optical
materials.After grinding and polishing, the elements are centered so that the
outer edge of the lens is perfect in circumference relative to the centerline or
optical axis of the lens.Bonded materials are used to make lenses with non-
spherical surfaces, and these lenses are called "hybrid aspherics." The
aspherical surfaces of these lenses are completed during centering.
Coating lenses
Formed lenses are coated to protect the material from oxidation, to prevent
reflections, and to meet requirements for "designed spectrum transmission" or
color balance and rendition. The lens surfaces are carefully cleaned before
coating. Some types of coatings include metal oxides, light-alloy fluorides,
and layers of quartz that are applied to lenses and mirrors by a vacuum
process. Several layers of coating may be applied for the best color and light
transmission, but excessive coating can reduce the light that passes through
the lens and limit its usefulness.
Producing the barrel
The barrel includes the chassis that supports the various lens elements and
the cosmetic exterior. Metal mounts, grooves, and moving portions of the lens
are critical to the performance of the lens, and are machined to very specific
tolerances. Lens mounts may be made of brass, aluminum, or plastic. If the
barrel is made of engineering plastic, it is produced by a highly efficient and
precise method of injection molding. The interior surfaces of the barrel are
also coated to protect them and to prevent internal reflection and flare.
Assembling the lens
Other parts of the lens, such as the diaphragm and auto focus module, are
produced as subassemblies. The iris diaphragm is constructed of curved
leaves cut out of thin sheets of metal. The metal leaves are held in place by
two plates. One plate is fixed, the other moves, and has slots for sliding pins.
These slide the leaves back toward the barrel to open the diaphragm or into
the center to close the opening as the f-stop ring is turned. The diaphragm
assembly is fastened into place when the lens mount is attached to the end of
the barrel. The auto focus is also added, the optical elements are positioned,
and the lens is sealed. After final assembly, the lens is adjusted and inspected
rigorously. Lenses may also be tested by subjecting them to shocks,
dropping, and vibration.
Quality Control
Quality and precision are essential to lens production, however, regardless of
manufacturing approach. Incoming materials and components are rigorously
inspected for quality and compliance with engineering specifications.
Automated processes are also inspected constantly and subjected to
tolerance checks. Hand-craftsmanship is performed only by skilled artisans
with long years of training. Some measuring devices are laser-controlled and
can detect deviations of less than 0.0001-millimeter in a lens surface or in
lens centering.
DISCLAIMER
The information is provided by Tecquisition for general informational and educational purposes only and is not a substitute for professional legal advice.
If you have any feedback, comments, requests for technical support or other inquiries, please mail us by tecqusition@gmail.com.
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