Telecentric Lens

A Telecentric lens, is a kind of lens that the chief rays are parallel to the optical axis. There are three kinds of telecentric lens, that is object space telecentric lens, image space telecentric lens, and bi-telecentric lens. Telecentric lens is always the core business of Canrill Lens. After continuous research and development for 11 years, Canrill has successfully developed 1700+ kinds of lenses, and the number is still increasing, to meet the diverse and growing applications.

Advantages Of Canrill Telecentric Lens

High telecentricity and little-to-no distortion for accurate measurements

Good consistency for better telecentric imaging

Extensive range of machine vision telecentric lens covering sensor size from 4.8mm to 82mm and supporting object FOV from 0.7mm to 390mm.

Considerable inventory offers the quickest leading time in industry

Quick customization service,break the customization record by producing a new lens within 12 days from design to finished product

World-famous brands endorsement, like Apple, Samsung, Huawei, Han's Laser, Foxconn, etc.

Telecentric Lens Tutorial

What is a Telecentric Lens?

The telecentric lens is mainly designed to correct traditional industrial lens parallax. Within a certain range, a telecentric lens for machine vision can make the image magnification of the image does not change. Currently, due to its unique parallel optical path design, the telecentric lens has been widely favored by machine vision applications that are highly required for lens distortion.

What's The Difference Between Resolution & Mtf30 For The Telecentric Lens?

Resolution and MTF have a different definition method.

Resolution formula is R=0.61*λ/NA. R is object resolution and λ is wavelength, which is usually 0.55um. NA is the numerical aperture of the object side of the lens.

For example, XF-MT1X65D, the NA is 0.045, thus the resolution is 0.61*0.55/0.045≈7.45um. ( the resolution in our product list and drawings is 7.33um, is because decimal point numbers )

Therefore the corresponding line pairs should be 1000/(7.33*2)=68Lp/mm.

MTF is Contrast of output image/Contrast of input image. Since the input image is always larger than the output image, therefore the MTF value is always from 0-1.

MTF30 means the line pairs when the image MTF value is 0.3.

So to calculate the image side resolution, the formula is 1/MTF30/2.

For example, XF-MT1X65D, the MTF30 is 90lp/mm, then the resolution is 1/90/2=5.56um.

What Is The Resolution Of Telecentric Lens?

Resolution is the ability to resolve details in the object. It describes the thinnest line that the human eye can distinguish. Normally, the resolution for machine vision telecentric lens is as below:

R=0.6*λ/NA;

λ is the wavelength of the light(normally λ is 550nm);

NA is the numerical aperture of the lens.

How To Improve The Deep Of Field (dof) Of A Telecentric Lens?

The DOF of a telecentric lens can be changed by adjusting its aperature. When the aperature gets bigger, the DOF becomes smaller. When the aperature gets smaller, the DOF will increase.

What's The Advantage Of Telecentric Lens System?

Telecentric Lens can eliminate the parallax error characteristic by having a constant, non-angular field of view. Its magnification and field of view do not change at any distance from the object.

Telecentric Lens has a very low level of distortion, which makes the telecentric lens an excellent choice for metrology applications

Telecentric Lens can have a larger depth of field, which is beneficial in maintaining a very good image contrast even when looking at very thick objects

Canrill is a professional optical lens manufacturer, we provide image space telecentric lens, telecentric lens image, machine vision illuminator, illuminator machine and etc. Want to know how to make a telecentric lens? Please contact us.