العدسات المغلقة .. كتاب أسس التصوير الضوئي

Coated lenses.Costed Lens

Photographic lenses are made of high-quality glass that is highly polished, which results in increased light reflections on the surface of the lens, and deprives us of the benefit of benefiting from some amount of light in addition to the bad effect of these reflections by reaching the rough layer. And to prevent these reflections prepared. Modern photographic lenses have a light blue layer, the purpose of which is to reduce these reflections. It is a very thin layer of a material that has a lower refractive index than the glass from which the lens is made. The composition of this material differs according to the factories that manufacture the lenses.

But it is often made of magnesium fluoride. (Magnesium Fluoride) namely

A layer that is easy to scratch, so it is good not to rub the lens when cleaning it, but it is enough

With a very soft mattress - or by blowing out the dust with a rubber blower These lenses are bluish in color. Factories have reached Recently, this thin casing has been made with a more solid material.

Light barrier for lenses: Lens Hood

In order to prevent damages resulting from the rays emitted from the sides that do not enter into the angle of view of the lens, a barrier has been prepared for cameras that can be installed on the lens to block direct light from it from all sides and prevent light from reflecting on it. So that its effect does not reach the sensitive layer..