is a compound lens which has its entrance or exit pupil at infinity. This means that the chief rays (oblique rays which pass through the center of the aperture stop) are parallel to the optical axis i [..]

A problem with digital camera sensors is that they separate colours by placing an array of colour filters in front of an array of light sensitive cells. This means that a light ray striking the sensor at an oblique angle can leak across into an adjacent cell, causing a degradation of the colour analysis (i.e., 'colour crosstalk'). The pro [..]

A type of imaging lens in which the exit pupil is located at infinity. As a result, within a certain range of working distances there is no viewing angle error or magnification error associated with f [..]