Characteristics and differences between industrial lenses and civilian lenses

Industrial Lens Characteristics and Classifications

An optical lens, generally known as a camera lens or photographic lens, has the primary function of optical imaging. Lenses are crucial components in machine vision systems, affecting key imaging quality indicators like resolution, contrast, depth of field, and various aberrations. The wide variety of lenses, combined with significant quality differences, means that choosing the right lens is crucial to system design success. Inadequate attention to lens selection can result in poor image quality or system failure.

High-Pixel Dual Telecentric Lens

Industrial lenses are akin to the human eye's crystalline lens. Without them, a camera's output would be a blank, unclear image. This is similar to how nearsightedness in humans results in blurred vision. The coordination between a camera and its lens is analogous: if the image is unclear, adjusting the camera's back focus (like adjusting the position of the crystalline lens) can make the image clearer. Hence, the role of the lens in a closed-circuit surveillance system is extremely important.

Installation Dimensions and Interfaces

All camera lenses have threaded mounts, with two common industrial standards: C-mount and CS-mount. While their threading is the same, the distance from the lens to the focal plane differs.

• C-mount: Distance from lens mounting reference to focal point is 17.526mm.
• CS-mount: This is a special C-mount, requiring removal of a washer from the camera's front before mounting the lens. The distance to the focal point is 12.5mm. To mount a C-mount lens onto a CS-mount camera, a 5mm extension ring is needed.

Lens Sizes

Lenses are available in different sizes, such as 1 inch, 2/3 inch, 1/2 inch, 1/3 inch, and so on. Auto-focus technology comes in three types: active infrared ranging, ultrasonic positioning, and solid-state triangulation.

• Active infrared auto-focus uses a light-emitting diode to emit a small infrared beam to the central area of the lens's field of view. The reflected infrared light is focused by a receiver lens onto two silicon detectors near the lens, allowing the microprocessor circuit to determine the distance between the target and the camera.

• Auto-focus lenses are not suitable for all situations. If the target doesn't reflect infrared light or reflects it in other directions, the auto-focus feature may not work.

• Stabilized lenses are used in security systems to compensate for camera shake or vibration. These are common in handheld cameras, vehicle-mounted cameras, airborne platforms, and ship-mounted systems. The internal mechanism counters camera movements to stabilize the image.

Consumer Lens Classifications and Characteristics

Lenses are typically categorized by focal length:

• Fisheye Lens: 180-degree view with significant distortion, used for special effects.
• Macro Lens: Captures small objects at close range, like ants.
• Wide-Angle Lens: Ideal for landscapes and large scenes with infinite focal range.
• Standard Lens: Suitable for general photography, sitting between wide-angle and telephoto.
• Telephoto Lens: Captures distant subjects, such as in sports photography.
• Super-Telephoto Lens: Useful for capturing the moon and stars.
• Zoom Lens: Has adjustable focal length, providing flexibility in composition.

Differences Between Industrial and Consumer Lenses

• Clarity: Industrial lenses tend to offer higher clarity, particularly in the image's center. Ordinary lenses tend to lose clarity at the edges. Factors affecting lens clarity include:

  • Material and purity of the lens: Fewer impurities result in clearer images.
  • Grinding precision of the lens: This determines the quality of the lens.
  • Coating precision: Affects light transmission and reduces aberrations.

• Spectral Transmission: Industrial lenses typically have broader spectral transmission, enhancing image contrast and brightness.

• Spectral Correction: High-quality lenses offer better spectral correction, allowing different wavelengths to accurately focus on the camera's sensor. This reduces virtual images and improves clarity.

These characteristics and classifications highlight the importance of proper lens selection in both industrial and consumer applications. Industrial lenses tend to be more specialized, focusing on higher precision and durability, while consumer lenses offer more versatility and ease of use.