Objective - Entocentric
Entocentric lenses have a fixed or variable (zoom lenses) opening angle of the optics to the object. They are used for presence detection and assembly control, pick and place applications, feature inspections, color applications, OCR-recognition and code reading. Due to their perspective error they are not suitable for measurement applications. Telecentric lenses are special optical lenses that are characterized by the fact that their entrance or exit pupil are located at infinity. They are mainly used for measurement tasks with high repeatability, especially when measuring is to be made without perspective distortion at fluctuating object positions (in excess of the field of view in x and y direction).