Camera optical lens involve number of items. Each lens is exposed to air. Reflection occurs when light is projected onto the polished surface of the lens. Air plays an important role in the reflection and light loss. When light travel through the lens and multiple reflections occurs, it inevitably produces some scattered light. This scattered light affects the image clarity and contrast. Deposited film can reduce light reflection which improves image clarity and contrast. This deposited film through the lens is called coated lens.