The Coordination Between Industrial Lenses and Light Sources

The coordination between industrial lenses and light sources plays a critical role in the development of high-performance machine vision systems. Achieving optimal imaging performance requires the comprehensive alignment of optical parameters, environmental conditions, and detection targets. The following outlines several key considerations for effective coordination:

I. Balancing Aperture and Light Source Intensity
The aperture (F-number) significantly affects the amount of light entering the system.
A small aperture (high F-number, e.g., F/16) reduces light intake and requires compensation through a high-intensity light source. Its primary advantage is an increased depth of field, making it suitable for applications involving objects with significant height variations.
Conversely, a large aperture (low F-number, e.g., F/2.8) allows more light to enter, making it ideal for low-light environments or high-speed motion scenarios. However, due to its shallow depth of field, it is essential to ensure that the target remains within the focal plane.

II. Optimal Aperture and Light Source Coordination
Lenses typically achieve their best resolution at medium apertures (approximately one to two stops smaller than the maximum aperture). At this setting, the light source intensity should be appropriately matched to maintain a favorable balance between signal-to-noise ratio and optical aberration control.

III. Synergy Between Depth of Field and Light Source Uniformity
When using a small aperture, it is recommended to pair it with a highly uniform surface light source (e.g., a diffuse reflection light source). This combination helps prevent localized overexposure or underexposure, ensuring image consistency under conditions requiring a large depth of field.
When using a large aperture, point or linear light sources can be employed to enhance edge contrast. However, careful adjustment of the light source angle is necessary to minimize stray light interference.

IV. Matching Resolution with Light Source Wavelength
For high-precision detection tasks, it is essential to select a light source that aligns with the spectral response characteristics of the lens. For example, visible light lenses should be paired with white LED sources, while infrared lenses should be used with infrared laser sources.
Additionally, the selected light source wavelength should avoid the absorption bands of the lens coating to prevent energy loss and chromatic aberration.

V. Exposure Strategies for Dynamic Scenes
In high-speed detection scenarios, combining a large aperture with short exposure times is often necessary. In such cases, a high-frequency pulsed light source (e.g., a strobe light) is recommended to effectively eliminate motion blur.
For applications requiring long exposure times, a stable continuous light source should be used, and measures such as polarizing filters should be considered to suppress ambient light interference and enhance image quality.