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 telecentric lens, image telecentric lens and bi-telecentric lens. Telecentric lens are always the core business of Canrill. After continuous research and development for 11 years, Canrill has successfully developed 1700+ kinds of lens, and the number is still increasing, to meet the diverse and growing applications.
Types Of Telecentric Lens
Advantages Of Canrill Telecentric Lens
Telecentric Lens Tutorial
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, λ is wavelength, usually 0.55um, NA is the numerical aperture of the object side of 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 ablility of resolving details in the object.It describes the thinnest line that the human eye can distinguish.Normally,it is defined in optics 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?
1. Telecentric Lens can eliminate the parallax error characteristic by having a constant, non-angular field of view, its magnification and field of view does not change at any distance from the object.
2. Telecentric Lens have a very low level of distortion, which makes telecentric lens an excellent choice for metrology applications
3. 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