In the field of industrial automation and machine vision, lenses, as the core component of the imaging system, are selected to directly affect image quality and inspection accuracy. Whether it is high-precision dimensional measurement or defect detection in complex environments, choosing the right industrial lens is a key step to ensure system performance. However, in the face of a wide variety of lens models and complex parameters and indicators, how to efficiently and accurately complete the selection, often become a challenge for engineers.

1. Defining application requirements

• Inspection object: Determine the size, shape, material and surface characteristics of the inspection target.

• Working distance: define the distance between the lens and the object.

• Resolution Requirements: Determine the required resolution according to the detection accuracy requirements.

•  

  Environmental conditions: Consider environmental factors such as temperature, humidity and vibration.

   

2. Selection of sensor size

• Select a matching lens based on the size of the camera's sensor to ensure that the imaging area covers the sensor.

3. Determination of focal length

• Field of View (FOV): Calculate the required FOV based on the size of the detected target and the working distance.

• Focal length calculation: Use the formula f = \frac{WD \times H}{H_{sensor}}f=HsensorWD×H to estimate the focal length, where WDWD is the working distance, HH is the height of the target, H_{sensor}Hsensor is the sensor height.

4. Selecting the aperture

• Aperture size: choose the appropriate aperture according to the lighting conditions, low-light environment requires a large aperture, high light environment can choose a small aperture.

• Depth of field requirements: large aperture shallow depth of field, small aperture depth of field, according to the detection needs to choose.

5. Consideration of lens types

• Fixed Focus Lens: Suitable for fixed working distance and field of view angle.

• Varifocal Lens: Suitable for scenes that require adjustment of field of view or working distance.

• Telecentric Lens: For high precision dimensional measurements and reducing perspective errors.

6. Assessment of optical performance

• Resolution: Ensure that the lens resolution meets the system requirements.

• Aberration: Choose a lens with low aberration, especially for high-precision measurement applications.

• Aberration: Evaluates chromatic aberration, spherical aberration, and other aberrations to ensure imaging quality.

7. Mechanical compatibility

• Interface type: Make sure the lens matches the camera interface, e.g., C port, CS port, etc.

• Size and weight: Consider installation space and mechanical stability.

8. Testing and validation

• Actual test: Test the lens performance in real environment to ensure that it meets the demand.

• Adjustment and optimization: Adjust the lens parameters or replace the model according to the test results.