1. When to use them, why you should use them, and how they work!
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Telecentric Lens:
When to use them, why you should use them, and how they work!

2. What is a Telecentric Lens?
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What is a Telecentric Lens?
In a telecentric lens, only light rays parallel to the axis of the light path get into the lens!
Telecentric Lens
Standard Lens

3. BENEFITS OF TELECENTRIC LENSES VS. NON-TELECENTRIC LENSES
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BENEFITS OF TELECENTRIC LENSES VS. NON-TELECENTRIC LENSES
- No magnification change with object position change!
1/10-1/100 magnification error compared to standard lenses!
- No perspective errors!
- Very low distortion!
Regular lens have 1-2% distortion, telecentric lenses have 0.1%
No edge position uncertainty due to object border lighting geometry!
Accurate measurement of points on the edge of the object.
- Better resolution!
Much higher MTFs found in Telecentric lenses!

4. OPTO ENGINEERING srl
Why Use a Telecentric Lens? ANY CRITICAL MEASUREMENT APPLICATION SHOULD INTEGRATE A TELECENTRIC LENS!

5. 4.1 Tubes, Shafts, Cylindric Parts measurement
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4.1 Tubes, Shafts, Cylindric Parts measurement
4.2 Engine Parts Measurement
4.3 Objects with holes
4.4 Screws, Nuts and Threaded Objects

6. When Should Telecentric Lenses be Used?
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When Should Telecentric Lenses be Used?
Whenever a object’s (thickness > 0.1* FOV’s diagonal) is being measured
When different measurements must be carried on different object planes
When the object to lens distance is not exactly known or when it cannot be previewed
When holes must be inspected or measured
When the image brightness must be perfectly even
When defects can be detected using a directional illumination and a directional “point of view”

7. BENEFITS OF BI-TELECENTRIC LENSES VS. SIMPLY TELECENTRIC LENSES
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BENEFITS OF BI-TELECENTRIC LENSES VS. SIMPLY TELECENTRIC LENSES
- True telecentricity (Bi Telecentricity, aka image side telecentricity) is not common on most telecentric lenses from other manufacturers! Bi Telecentric lenses have the following advantages:
- Constant Magnification
Non Bi Telecentric lenses can have lot to lot differences of up to 3% difference on their magnification!
- Even Detector Illumination
True ‘flat field’ constant grey level illumation across the entire detector.
- Increased Field Depth
Bi Telecentric lenses keep excellent focus and contrast when looking at ‘thick’ objects!

8. OTHER TECHINCAL INFO - Telecentric Lens size
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OTHER TECHINCAL INFO
- Telecentric Lens size
Large; the diameter of the lens must be >= size of the object!
- Working Distance
Precisely set.
- Collimated Illumination
Eliminates edge effects, increased depth of field

9. ADVANTAGES WITH OPTO ENGINEERING TELECENTRIC LENSES
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ADVANTAGES WITH OPTO ENGINEERING TELECENTRIC LENSES
- Highest Performance/Price ratio
- Bi-telecentric Design
- Each lens is carefully Quality controlled
- Wide Range of models
- Opto Engineering can easily provide Custom Solutions
- Compact and robust design, with features which improve optical performances
– Fully integrated LED illuminators catalogue
– Easy Filter Integration