In industrial vision inspection systems, the selection of telecentric lenses directly impacts the success or failure of measurement solutions. An appropriately chosen telecentric lens enables high-precision, high-stability measurements, while improper selection may lead to project failure or cost wastage. Understanding how to scientifically select telecentric lenses is a core skill every vision engineer must master.

Key Considerations for Selecting Telephoto Lenses

1. Working distance refers to the distance from the front of the lens to the measured object, constrained by installation space and lighting arrangements;

2. Measurement range is determined by both field of view size and resolution, requiring that the measured feature be fully within the field of view;

3. Resolution requirements must match the minimum feature size, typically requiring 2-3 pixels to cover the smallest feature;

4. Distortion rate directly impacts measurement accuracy; select high-performance lenses with distortion below 0.1% for dimensional measurements.

Matching application requirements is the core of selection.

For high-precision dimensional measurement, prioritize dual telecentric lenses, whose magnification remains constant regardless of object distance, making them particularly suitable for thickness measurement and 3D positioning.

For surface defect detection, consider the lens's depth of field range and edge contrast to ensure clear imaging across the entire inspection surface.

For large-object measurement, multiple lenses may need to be stitched together, or specially designed large-field-of-view telecentric lenses should be selected.

System integration considerations are equally important. Factors such as lens-to-camera interface compatibility, compatibility with lighting systems, and the mechanical stability of the entire vision system must be evaluated. For high-speed inspection applications, it is also necessary to assess whether the lens's light transmission capacity meets the requirements for short exposure times.