Stephen Ingraham (who?)

the unofficial site for birders and digiscopers using Zeiss equipment.

The Truth About Quality

One reason Zeiss products are “better” than run-of-the-mill optics is the amount of hand labor involved in their manufacture and assembly.

Beginning at the design stage, experienced product managers and market specialists meet to determine, based on field experience and feed-back, what products will meet the needs of our current and future customers. Design specifications and criteria are developed.

Mathematical designs, both optical and mechanical, are produced, based on the specifications and criteria above, and then prototypes are built.

Prototyping is an art, and we have a separate group of technicians who take primary responsibility for hand-crafting the first working models of components and full optical systems. Prototypes are then individually tested by experienced engineers and market specialists, all of whom are end-users of the products being designed, and adjustments are made to the design until all design criteria are met, and the product specialists are satisfied.

As much time goes into designing the manufacturing and assembly process as goes into the design of the product.“Quality assurance” techniques are developed; jigs and testing equipment are built or adapted for each stage of assembly.

Our lenses are ground on precision diamond tip CNG machines. Each bank of two machines is run by an experienced master craftsman, generally assisted by an apprentice. The German apprentice tradition insures that no one operates a precision machine until they have had several years of direct experience working with the actual machine under a master craftsman. The CNG engineer is personally responsible for the operation and maintenance of his machine: and for tolerances and production goals being met.

Lenses are finished and cleaned by hand, and coated in the most up to date electron beam vapor chambers. The coating process can require several man-days per lens surface, and each layer is meticulously checked before the next layer is deposited.

Glass-fiber reinforced body parts are cast in computer controlled casting machines that are so sophisticated that engineers are able to specify the direction of the reinforcing fibers within the mold. The molds themselves require many man-hours of precision labor and are one of the most expensive single “components” in the production process. Mold making, like prototyping, is closer to an art than a science.

Metal parts are turned or milled on CNG lathes and milling machines, again, each bank tended by highly trained master mechanics and their apprentices.

Often the finish work on plastic molded parts is done on the CNG machines as well.

When the components are all finished, assembly begins. Assembly is done in “clean-rooms” by experienced technicians, most with years of experience. Our optics are essentially hand assembled. Each part is cleaned one more time, and then fit into the body or lens assembly by hand, and each component, as it is assembled, is tested for correct assembly and alignment. Testing procedures take close to half of the technicians’ time. A component or module only goes on to the next stage of assembly when it has passed its individual quality assurance tests.

Again, the design of the quality assurance tests, the testing jigs and apparatuses, requires as much attention as the design of the product itself.

Assembly of a binocular can require 8 hours, during which time it and its components are handled by 15-20 technicians.

Once a binocular is fully assembled it passes through a separate Quality Assurance Department, where, again, trained technicians test is overall performance to make sure it meets specifications and design criteria. We operate a veritable torture chamber for optics, exposing them to conditions and demands several times more severe than we expect our customers to ever experience in the field.

Of course, we use only the highest quality materials, and employ the most up-to-date machinery, but when building the finest optical instruments, there is no substitute for this kind of hands-on attention to detail and quality. Machines alone just don’t do the job: it requires a human eye and a human touch, and a human commitment to quality at every stage of the process, to produce the kind of optics that Zeiss is known for, worldwide.

We are confident that our customers experience and appreciate the difference in quality. Most, however, are not aware of the hundreds of individual hands and minds that make that quality possible.

So, next time someone asks you, “What makes Zeiss binoculars so good?” (Or, for that matter, “What makes Zeiss binoculars so expensive?”) remember the hundreds of hours of labor, the hundreds of careful hands and conscientious minds that are reflected in every Zeiss product.

We are Zeiss. We have been producing high-quality optics for 158 years, employing our hands and minds to push back the boundaries of optical excellence. We don’t know any other way to make the kind of optics we can put our name on.

Or at least that's the way I see it.