The Nikon PC NIKKOR 19 mm f/4 E ED Lens is a first-of-its-kind lens that can be tilted parallel or perpendicular to shift. It comes with a new PC Rotation capability that enables you to rotate the lens at a 90° angle. This lens is perfect for shooting panorama pictures, as well as pictures of architecture, landscapes, and interiors. The anti-reflective Nano Crystal Coat uses fine, nano-sized crystal particles for eliminating reflections inside the lens. Also, the lens is equipped with 3 Extra-Low Dispersion (ED) glass elements and 2 Aspherical glass (AS) elements that eliminate unwanted chromatic aberration and coma, even in wide aperture settings.
The individual pieces of glass that form the overall optical construction. Most lenses have between four and eleven elements to bend the light rays to ensure a perfectly formed image appears on the light sensitive surface, such as a film or CCD. The elements are arranged in groups and may be seen in specification sheets as, for example, 6 elements in 4 groups. That configuration may have two single elements and the other four grouped in pairs.