Why is the Telecentric Imaging Lens Dominating High-Precision Measurements?
Having exceptional measurement accuracy is an imperative element of scientific measurement. Standard illumination techniques in metrology, such as coaxial and diffuse illumination, can lead to measurement errors. The telecentric imaging lens is gaining immense popularity as a key element in high-precision optics in various industries. Furthermore, from the production of precision electronic elements to the final inspection of aeronautics parts, a machine vision telecentric lens has become a standard feature in numerous high-precision measuring instruments due to its exceptional performance.
However, in the broader world of optics, telecentric lenses represent an imperative advancement, especially in applications requiring high accuracy and precision. Additionally, these lenses are created to maintain a stable magnification across a wide range of distances. Thus, telecentric lenses are ideal for precision and detailed measurements. Nevertheless, in this comprehensive blog post, we will discuss why and how an industrial cameras lens is essential & dominating in high-precision measurements.
Vital Reasons Telecentric Imaging Lenses Excel in High-Precision Measurements
For precise measurement, accuracy is the key, and this is where telecentric imaging lenses excel. A machine vision telecentric lens is gaining acceptance in the industry for inspection, metrology, and quality control, as they provide accurate results without distortion.
1. Perspective Error Becomes Almost Zero
Another common problem with conventional lenses is that of “perspective error.” That is, if the object being photographed is moved slightly closer to or farther from the camera lens, its image size changes, so measurements are no longer accurate. A telecentric imaging lens has removed this problem entirely. In these lenses, light rays are always parallel to each other. It explains why an object keeps the same size no matter its position. It is particularly important in high-precision metrology because differences of microns are crucial.
2. Constant Magnification is Available
One of the great benefits of a telecentric imaging lens is that the magnification power is constant. It implies that, regardless of whether the object is slightly higher or lower, the magnification level will remain unchanged. It is a significant factor in automated measurement systems, where accurate measurement of size for all parts is required.
3. Edge Definition is Sharp
Sharp edges are imperative for accurate measurement. Furthermore, telecentric lenses have high contrast in capturing object edges. The use of parallel lighting minimizes shadow and blur, making edges easier to detect by computer vision algorithms and improving measurement accuracy.
4. Protection from Parallax Error
Parallax errors arise when the viewing angle varies even slightly. It is a frequent issue involving normal lenses, particularly when inspecting manually. That is why telecentric lenses offer straight-line viewing, consequently eliminating parallax errors altogether. Additionally, its direct advantage is more accurate measurements.
5. Depth of Field Remains Predictable and Controlled
The industrial cameras lens has a controlled depth of focus. It is helpful for measurement and analysis. It does not mean that the total image or object will be in focus, but it ensures that the measurement plane itself stays in focus. Moreover, it eliminates the background noise associated with focus, which is very important for accurate inspections.
6. Measurement Repeatability
Repeatability is essential in high-precision applications like electronics, automotive, and healthcare sectors. Telecentric lenses always produce identical results in a given setup. Thus, when you take measurements of a different object more than once, the results come out to be nearly identical. It is useful in statistical process control.
7. A Perfect Fit for Automation & Machine Vision
Automation has remained integral to modern production systems. A machine vision telecentric lens is compatible with automated robots and vision-guided robots, as well as automated metrology systems. It is because distortion and perspective distortions have been eliminated. Therefore, the image processing software does not require complicated correction processes.
8. Calibration is Constant
In standard lenses, frequent adjustments are needed, as even minute changes in setup parameters can impair measurement accuracy. Telecentric lenses offer constant geometric properties and a long calibration interval, which is a significant benefit for industry, as it requires less downtime for maintenance.
9. Suitable for Complex & Micro Components
Telecentric lenses are especially useful for imaging very small or intricate parts. Measurement of micro holes, grooves, threads, or edges becomes relatively easy when telecentric lenses are used. Moreover, a telecentric imaging lens is commonly used in areas such as semiconductor wafers, precisely machined components, and even biocompatible implants, as they can produce intricate details without distortion.
Technical Specifications of a Typical Telecentric Imaging Lens
| Specification | Description / Typical Values |
|---|---|
| Lens Type | Telecentric (Object-side or Image-side telecentric) |
| Magnification | 0.5× – 10× (depends on model) |
| Working Distance | 50 mm – 500 mm |
| Field of View (FOV) | 10 mm – 100 mm |
| Numerical Aperture (NA) | 0.05 – 0.25 |
| Resolution | Up to 5 µm |
| Distortion | <0.1% (essentially distortion-free) |
| Depth of Field (DOF) | 5 mm – 50 mm (depends on magnification and NA) |
| Wavelength Range | 400 nm – 700 nm (visible) or NIR/IR models available |
| Aperture Type | Fixed / Adjustable |
| Mount Type | C-Mount, F-Mount, M42, or custom |
| Coating | Anti-reflection coating for high contrast |
| Application | Machine vision, inspection, metrology, microscopy |
| Weight | 200 g – 1.5 kg (depends on lens size and design) |
Fundamental Role of Telecentric Lenses in Various Applications
The telecentric imaging lens plays a significant role in the current advanced industrial and scientific era. Telecentric lenses are applied in industries for quality inspection and measurement. Hence, telecentric lenses help clearly identify the object’s edges, enabling the machine to detect defects, cracks, or size differences. Telecentric lenses have applications in automation and machine vision as well. The image-size uniformity required by robots and automated cameras scanning the product is essential.
Telecentric lenses capture images of the same size and shape, regardless of how much the object to be scanned changes position. A machine vision telecentric lens can also be applied in scientific uses. Telecentric lenses are applicable in accurate observation in microscopy, medical imaging, and scientific research labs. Thus, they can be used in biological and materials science applications, where they produce accurate measurements and enable sample formation. Likewise, telecentric lenses can be used as a very effective tool in current industry and scientific applications. With their high precision, distortion-free imaging, and accurate measurements, such lenses play a critical role in advanced systems.
Let’s Conclude Here!
We hope this comprehensive blog post has provided you with the details you need on why a telecentric lens is essential for high-precision measurements. Furthermore, their precise ability to eliminate parallax errors and maintain a stable magnification has made them a foundational technology across various industries where advanced precision is paramount. As technology continues to develop advanced platforms, the potential applications and capabilities of telecentric lenses are set to expand, making them increasingly significant in high-precision imaging.
Nevertheless, if you are searching for a reliable platform to purchase an advanced telecentric imaging lens for industry applications, look no further than Superior CCTV. We offer a wide range of lenses suitable for enhancing security surveillance across various industries. So, what are you waiting for? Connect with us today!
Frequently Asked Questions
Ans: Telecentric lenses have constant magnification and no parallax errors. Therefore, the size of objects doesn’t vary with distance. Telecentric lenses are ideal for applications that require precise vision measurements because they maintain a constant magnification, as the light rays are parallel to each other. At the same time, standard lenses are used in common photography because they create perspective.
Ans: Unlike regular lenses with an entocentric perspective, in a telecentric perspective, the beam path prior to the entrance lens becomes parallel to the optical axis. As a consequence, the magnification remains constant throughout the depth of the field.
Ans: Telecentric lenses typically exhibit smaller system alignment errors than fixed-focus factory automation lenses, so they also merit consideration as single-surface lenses that require dimensional measurement.
Ans: Telecentric lenses provide adequate magnification and thus high image quality with less distortion and a large depth of field. These lenses perform well in measuring detail, irrespective of the distance, which is essential in industries such as photolithography.
Ans: When we consider a telecentric lens, we find that the aperture stop is located at the lens’s focal point. It is due to the distinct feature of the aperture stop that the light rays, which form the images of the aperture stop, appear at infinity because they are parallel to the optical axis.
