Effectiveness and impact of the lens coating

Why does the lens need coatings? Because any object has a reflection role for light, even colorless transparent glass has no exception. The difference lies in whether the angle of light will form a reflection effect. For the ideal state of the lens, the light can be completely through the lens and correctly focused in the film or CCD. However, the fact is that each of their lenses are subject to physical constraints, resulting in the generation of aberration, so many problems by the combination of camera lens that is not possible. Theoretically all the various angles of light magnesia completely through. Lanthanum oxide optical glass as an example, the transmission rate can reach 90%, and the remaining 10% will be reflected off the formation of glare. To compensate for this loss, the researchers developed a subsequent lens surface coated with a layer of the lens membrane to increase the light effect.

Although in the 1950s, designers can reduce glare coating to know the incidence, but also can enhance the image contrast and reduce the photo-blooming. But because of no appropriate processing technology. Therefore, the optical lens coating has always been only the highest level of the camera lens was entitled to the honor. Until 1968, a new generation of coating technology was developed to allow cheap coating process and the implementation of standards can only make the increasingly popular with the lens coating. In 1970 as a watershed in the development of coating technology, we can understand the technical differences before and after.

In order to meet the requirements of photography, the lens is often necessary to modern multi-layer coated on the film. Different functions of these membranes nickel oxide can be broadly divided into seven categories: antireflective film, reflective film, filter membrane, polarized film, protective film and the electric membrane. The modern multi-layer technology can be broadly traced back to 1971 by Asahi (PENTAX) Optics developed SMC (super multi-layer) technology, in 1971, the application of this technology Takumar lenses in many large photography exhibition limelight. Nikon was already a three-layer coating technology, coating technology in more than five theoretically feasible. Japan's Canon and German Leitz (Leica's predecessor) is also similar to the positive development of coating technology, but the limit of 7-layer coating is still very difficult to break through the bottleneck. On the other hand, Fujifilm claimed they developed an electronic beam coating EBC (electron-beam coating) claims up to 11 layers. Until Asahi (PENTAX) published shortly after the SMC technology, Fujifilm will soon EBC coating technology into photography lens manufacturing.