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A telecentric lens is a special optical lens (often an objective lens or a camera lens) that has its entrance or exit pupil, or both, at infinity. The size of images produced by a telecentric lens is insensitive to either the distance between an object being imaged and the lens, or the distance between the image plane and the lens, or both, and ...
Telecentric lens. Compound lens with an unusual property concerning its geometry of image-forming rays. In machine vision systems telecentric lenses are usually employed in order to achieve dimensional and geometric invariance of images within a range of different distances from the lens and across the whole field of view. Telephoto lens. Lens ...
Secondly, it only applies to an object-space telecentric lens. Third, it loses the point of how a telecentric lens actually works. What makes a lens telecentric is not that all the rays are "about parallel" to the optical axis. The properties of a telecentric lens come specifically from the fact that the chief ray is parallel to the axis.
English: Comparison of a conventional lens (1), object-space telecentric lens (2), image-space telecentric lens (3) and bi-telecentric lens (4), assuming the images are in sufficient focus by CMG Lee.
A hypercentric or pericentric lens is a lens system where the entrance pupil is located in front of the lens, in the space where an object could be located. In a certain region, objects that are further away from the lens produce larger images than objects that are closer to the lens.
Similarly, the allowed range of angles on the output side of the lens can be filtered by putting an aperture at the front focal plane of the lens (or a lens group within the overall lens), and a sufficiently small aperture will make the lens image-space telecentric. This is important for DSLR cameras having CCD sensors. The pixels in these ...
A camera lens adjusted for large and small aperture. The visible opening is the entrance pupil of the lens. The apparent location of the anatomical pupil of a human eye (black circle) is the eye's entrance pupil location. The outside world appears to be seen from the point at the center of the entrance pupil.
The lens design can be changed even more: in colour apodization the lens is modified such that each colour channel has a different lens aperture. For example, the red channel may be f /2.4, green may be f /2.4, whilst the blue channel may be f /5.6. Therefore, the blue channel will have a greater depth of field than the other colours.