Some problems in practical application of telecentric lenses

Telecentric Lens Benefits:

• Telecentric lenses are designed using the Telecentric principle, characterized by low distortion and no perspective error. This design is ideal for industrial measurement applications, leading to higher costs compared to ordinary lenses. Telecentric lenses also feature coaxial lens designs, offering different working distances and magnifications.

Why are Low-Magnification Telecentric Lenses More Expensive?:

• To reduce distortion and allow parallel light entry, telecentric lenses are designed to be larger than the objects being imaged. Consequently, low-magnification lenses typically have larger apertures, requiring more expensive lens materials, resulting in higher costs.

Why Does a Coaxial Light Lens Produce a Brighter Center and Darker Edges?:

• The coaxial light in these lenses is concentrated in the central 5-6mm area. If the viewed range is larger, the edges may appear darker, which is common with low-magnification coaxial lenses. Adding a ring light source can help compensate for the lack of light on the edges.

Can Telecentric Lenses Be Used with 2x CCTV Lenses?:

• It is possible but not recommended. Adding a 2x lens to a telecentric lens can degrade image quality and require stronger light intensity.

What Does "Lens Resolving Power" Indicate in Telecentric Lens Specifications?:

• Resolving power is the lens's ability to distinguish the smallest object edges. If the resolving power is too low, the object cannot be clearly observed, indicating a need for higher magnification lenses such as high-power microscopic objectives.

Why Can't Telecentric Lenses Have a Long Depth of Field?:

• Telecentric lens design balances depth of field, magnification, aperture, and working distance to achieve optimal results. To increase the depth of field, you might have to sacrifice other parameters, impacting lens quality.

What Kind of Lens Can See Objects as Small as 1μm?:

• To view objects smaller than 1μm, high-power microscopic objectives are required. However, they have shorter working distances (around 7mm) and shallow depths of field.

What is the Actual Magnification of Images Captured by Telecentric Lenses?:

• The actual total magnification of an image is the product of the optical magnification of the lens and the monitor magnification. Monitor magnification is calculated by dividing the monitor's diagonal by the CCD sensor's diagonal (e.g., a 1/3-inch CCD sensor displayed on a 14-inch monitor is about 59.3 times magnification).