Some photographers usually put a skylight or UV filter on their lens to correct or eliminate the blueish cast caused by ultra-violet lights in the atmosphere. However, Leica developed a special cement call "Absorban" for cementing elements in a lens. Absorban also has the property of absorbing ultra-violet light, thus making a UV filter unnecessary, except at extreme altitudes or to protect the front surfaces of a lens under adverse conditions.

 APO means different things to different lens manufacturers. Leica apply very rigid standards to all their lenses. All Leica APO lenses are fully apochromatically corrected, i.e. all colors, including infra-red, are brought to focus at the same point. In other words, once focusing is done through the viewfinder, no manual correction is needed when taking pictures with infra-red film.

 As a standard "burn-in" QC check, every Leica camera is put through 6 temperature cycles between -25 and +60 degree C (-13 to 140 degree F), and all individual functions are then tested. Only 100% pass is acceptable.

 All Leica R-lenses are designed to be used without restrictions from -25 to +60 degree C (-13 to 140 degree F) while retaining full optical performance.

Every Leica R-cameras is designed to provide precise functioning even after a minimum of 100,000 exposures. The aperture mechanism on R-lenses should show no detectable sign of wear after a minimum of 50,000 cycles. The R-lens bayonet should show no wear for a minimum of 10,000 lens change.

Some characteristics of Leica lenses: Focusing and aperture controls are extraordinary smooth. The automatic diaphragm even under the load of motor drive operation gives repeatable performance. Results from different focal lengths exhibit neutral color rendition. Any one of the lenses can be rested directly on their bases because there are no protruding levers or other components. Special lubricants insure smooth functioning over wide temperature extremes. The maximum aperture is a fully effective working aperture; it is not for decoration.

Let me know if you have other trivia to share. I look forward to seeing your e-mail.

Back to my home page

This page hosted by   Get your own Free Home Page