What are the advantages of lenses that are specifically designed for digital camera use?
Although the small size of the individual pixels in CCD, CMOS, and Live MOS image sensors enables them to capture even more detail than film, the sensitivity of the sensor elements is highly directional. That is, they respond best to light that strikes the elements straight on. With lenses designed for use with film, the light rays passing through the periphery of the lens strike the image sensor at an angle, and this tends to degrade picture quality at the periphery of the image area. On the other hand, lenses developed specifically for digital cameras are designed to match the imaging characteristics of CCD, CMOS and Live MOS sensors, ensuring high image quality at both the center and the periphery of the frame.
