This Chapter gives information about the optics and the sensor in an image acquisition
system. Optic is the first stage of the image acquisition system and is composed by one or more
lenses aiming to concentrate the light in the physical sensor obtaining an in focus image. It is one
of the most expensive parts of an imaging system. In mobile cameras usually a lens is compound
of a system of plastic and glass lenses stacked together, while in single lens reflex cameras (SLR)
a group of several glass lenses system is employed to reduce image artifacts. In this Chapter
an overview of the lenses will be discussed. Moreover, some typical artifacts will be introduced
(e.g., cross talk and chromatic aberration). The sensor is the part that converts the optical image
(light) to an electric signal. There are several kinds of sensors depending on the technology
(CCD - Charge Coupled Device and CMOS - Complementary MetalOxideSemiconductor), on the
color filter array (Bayer , Foveon, 3CCD, Panchromatic), on the transducer function (LDR - low
dynamic range, WDR - wide dynamic range and HDR - high dynamic range sensors).
