All machine vision lenses (either telecentric or not) show some amount of distortion. In addition to barrel or pincushion distortion, changes in the view angle or misaligned components will affect the image symmetry and generate the so called thin prism or keystone effect.
Distortion can be software-corrected by analyzing the image of a precision pattern whose geometrical features are well known. Opto Engineering® offers a full range of calibration patterns optimized for software calibration compatible with most Opto Engineering® telecentric lenses.
The checkerboards are realized with two different processes in order to provide the best solution depending on the requirements:
Chrome on glass, for leading edge applications;
Emulsion on glass, for a perfect synthesis of performance and cost effectiveness.