Are all telecentric lenses fixed-magnification and fixed-focus?

Not all telephoto lenses are fixed-magnification and fixed-focus. Conventional telecentric lenses are usually designed with a fixed magnification and fixed focus, while varifocal telecentric lenses (such as the 55mm varifocal model) have an adjustable focal length.

Conventional telecentric lenses are fixed-magnification lenses with a fixed magnification ratio. This design ensures extremely high stability and consistency in imaging, making them particularly suitable for applications where strict requirements are placed on image size and proportion, and where the size of the object being imaged is relatively fixed. For example, in industrial inspection, conventional telecentric lenses can ensure consistent imaging results across different batches of products, thereby improving the accuracy and efficiency of inspection.

Unlike conventional telecentric lenses, varifocal telecentric lenses have an adjustable focal length range. Take a 55mm varifocal telecentric lens as an example. Its maximum adjustable focal length reaches 55mm, and it can change the magnification and imaging range within a certain range. This feature allows varifocal telecentric lenses to adapt to the imaging needs of objects of different sizes without frequent lens changes, thereby improving the flexibility and efficiency of inspection.

Key differences between conventional and varifocal telecentric lenses

1. Optical structure：Conventional telecentric lenses use a fixed optical structure, and their focal length and magnification cannot be adjusted. Varifocal telecentric lenses, on the other hand, use complex mechanical devices and optical elements to change the focal length while maintaining the telecentric optical path characteristics.

2. Imaging flexibility：Conventional lenses are limited to a fixed magnification and are only suitable for detecting objects of a specific size. Zoom lenses can cover a wider imaging range by adjusting the focal length, adapting to the detection requirements of objects of different sizes.

3. Application scenarios：Conventional lenses are more suitable for scenarios where the object size is fixed and the detection requirements are simple. Varifocal lenses have significant advantages in environments where it is necessary to quickly switch between detection objects or process products of multiple specifications, such as multi-product production lines or R&D testing stages.