The light receptors in digital SLR cameras are located towards the back of the image sensor. (*) Due to this construction, light entering from a non-perpendicular inclined angle does not fully reach each receptor, causing a lack of luminosity and lowers resolution.

With film cameras, the light reception occurs on the surface of the film and thus light entry from an inclined angle does not pose a problem. As a result, lenses developed for film SLR cameras are not designed to ensure a perpendicular ray of light, as this was un-necessary. When using such a lens on a digital SLR camera, however, the rays of light entering at an angle do not fully reach the light receptors. This becomes an increasing problem with wide angle lenses as visible around the perimeters.

“ZUIKO DIGITAL” lenses are designed exclusively for digital SLR cameras, allowing all necessary light to hit the image sensor at a perpendicular angle. This means that even with wide angle lenses, decreases in light in perimeter areas can be limited to a minimum, allowing for high quality images. At the same time, it allows even super-telephoto lenses to be compact and excel in mobility.

* What is an image sensor? = These are image sensing devices such as CCD and CMOS sensors.