Whether for cameras, binoculars, or a video projector for showing a football match on a big screen, sharpness is paramount in optical devices. The best picture quality comes only from first-class optical lenses, and modern compact devices provide this in a mini version. The vital components in optical devices are the lenses: those that are highly refractive, and those that correct geometric and colour defects, or ‘aberrations’.

Special raw materials

Phosphates with the highest purity can be used in manufacturing optical lenses for a perfectly clear view. Optical glass often gets its highly refractive properties from the addition of bismuth, molybdenum or niobium. However, these substances tend to crystallise, which destroys the amorphous, homogenous glass structure. Phosphates are also excellent glass formers, which fix the heavy-metal ions in the glass matrix, giving a crystal-clear view. This is also true for correction lenses, which balance out optical and colour aberrations in geometric lenses. Fluoride-based lenses are used to correct colour aberrations. However, these also tend to crystallise without the addition of phosphates. In addition, compared with other types of glass, a significantly broader colour spectrum is possible with phosphate glass.

Producing optical glass is a very precise science. Even miniscule impurities, such as metals like iron, can lead to transmission losses or even colour aberrations. That is why phosphates from Budenheim, with their excellent purity levels, are particularly appreciated.