In order to deliver optimal image quality and to safeguard the high demands of lens/camera manu- facturers, B+W glass filters are manufactured virtu- ally exclusively from glass supplied by the German Schott Group.
Constant quality controls during manufacturing and an obligatory final inspection of every filter before it is sent to distribution assure the re- nowned high quality standard – The term ”Guarantee“ is taken very seri- ously at B+W. A supposedly attractively inexpensive filter, on the other hand, can easily degrade the good imaging performance of a lens. Image quality really does already begin before the lens!
Not only the high optical performance is important to measure the quality of a filter. Important as well are material and quality of production of the filter holder. This is why B+W in production only uses metal, precisely turned on CNC-controlled machines, almost without production tolerances. The solid metal holder as well as the precise screw thread are guarantee for a long filter life.