This is also applicable to objects with depth. Also called parallax, this is a phenomenon in conventional lenses which causes a change in magnification as it moves in and out from best focus. Closer objects appear larger than objects further away. Telecentric lenses optically correct for this occurrence. The size of a camera sensor's active area, typically specified in the horizontal dimension.
Resolution is a measurement of the imaging system's ability to reproduce object detail.
Figure 2 illustrates a simplified view of two squares imaged onto pixels of a CCD camera. In order for two objects to be resolvable, a certain amount of space between the objects is needed. This specification can be used for both lenses and cameras. In other words, for two red squares to be resolved, one pixel needs to be dedicated to each red square and one to the blank white space between them. In analog CCD cameras, this is a unit of resolution based on a bar target with equally spaced lines.