High-precision tape measurement system using a camera

There is no expansion or contraction of the image within the depth of field.
Measurement errors can be minimized when measuring dimensions.
Less image distortion due to parallax
There are two main types of telecentric lenses.
Bilateral telecentric lenses and unilateral telecentric lenses.
The features of each are as follows.

Bilateral telecentric lens

It has the characteristic that the projected size of the object does not change regardless of the distance between the camera sensor side and the object side.

In other words, by changing the distance on the camera sensor side using a close-up ring, etc., you can change only the distance between the lens and the object without changing the magnification.

However, the diameter of the lens is physically larger than the area to be projected, so the lower the magnification, the larger the lens size and the higher the price.

Used in precision measuring equipment and projectors.

Object-space telecentric lenses

This lens has a telecentric lens structure only on the object side.

Unlike Bilateral telecentric lens, when the distance to the camera sensor side changes, the projected size of the object changes, similar to non-telecentric lenses.

The lens is smaller and less expensive than Bilateral telecentric lens.

If changing the magnification like a macro zoom lens is not necessary for dimension measurement purposes, it may be used as a fixed magnification replacement.