In the field of machine vision, the choice of lens is crucial, which is directly related to the imaging quality and measurement accuracy. However, in practical applications, people often confuse the use of ordinary telecentric lens and double telecentric lens both, which may lead to the actual application can not give full play to the performance advantages of the lens. In order to help you better understand the differences between these two types of lenses and their respective applications, the next will be from the principle of difference, the appearance of the difference and the difference in the visual measurement of the three aspects of the detailed analysis:

Principle Differences and Similarities

Principle Differences:

(1) Double telecentric lens: telecentric in both object and image sides, which can better eliminate parallax, smaller and more uniform imaging aberration, greater depth of field, and a wider range of working distance. This design makes the double telecentric lens has a fixed magnification when imaging, not affected by the position of the object, thus improving the accuracy and stability of the measurement.

(2) Ordinary telecentric lens: usually only with the object side of the telecenter, imaging accuracy and stability is relatively weak. It corrects the visual aberration to a certain extent by placing an aperture diaphragm at the focal point of the optical system so that only light rays parallel to the optical axis can be captured by the optics.

Same Point:

Both feature a telecentric design designed to improve imaging accuracy and stability, and can be applied to machine vision inspection programs, especially where high-precision measurements are required.

Appearance Differences

(1) Double Telecentric Lens: Since it is necessary to realize telecentric design in both object and image sides, its structure may be more complicated and its volume may be relatively large.

(2) Ordinary Telecentric Lens: Relatively simple structure, may be smaller in size, easier to install and use.

Differences in visual measurements

Imaging Quality:

(1) Double telecentric lens: imaging aberrations are smaller and more uniform, providing a higher quality image and thus improving the accuracy of the measurement.

(2) Ordinary telecentric lenses: Although they can also provide relatively clear images, they may be slightly inferior to double telecentric lenses in terms of imaging quality and stability.

Measurement Accuracy:

(1) Double telecentric lens: With fixed imaging magnification and greater depth of field, it can provide more accurate measurement results, especially when measuring objects that are not on the same plane.

(2) Ordinary telecentric lens: Measurement accuracy may be affected by the position of the object, distance and other factors, relative to the double telecentric lens may have a certain error.

Applicable Scenarios:

(1) Double telecentric lens: more suitable for high-precision measurement, three-dimensional object measurement, and the need for low distortion rate, image effect brightness almost identical occasions.

(2) Ordinary telecentric lens: suitable for general telecentric needs occasions, such as the measurement of flat objects, simple machine vision inspection.