August 15, 2025
When designing a high-performance optical system, choosing the right lens is only half the story. One critical—but often underestimated—factor in achieving optimal image quality is understanding the sensor that the lens will serve. More specifically, both the sensor format and its manufacturer play foundational roles in determining how a lens will perform across the imaging field.
At Westech Optical, ensuring precise optical alignment starts from the ground up—with your sensor specs.
Sensor Format: Not All Standards Are Created Equal
You might think that selecting a sensor labeled "1/2.5-inch" or "1/3-inch" standardizes your design process. However, sensor formats are not industry-standardized in physical dimensions. Two sensors labeled 1/3", for instance, may have different active image areas, diagonal measurements, and even aspect ratios depending on the manufacturer.
These seemingly small deviations can significantly affect:
- Field of View (FOV): Changing the sensor's physical size alters how much of the scene the lens captures.
- Image Circle Coverage: If the sensor is larger than expected, vignetting may occur; if it's smaller, you're not making full use of the lens.
- Corner Sharpness: A mismatch between sensor size and the designed image circle can reduce edge-to-corner resolution.
Why Sensor Manufacturer Matters
Even within the same format, different manufacturers engineer their sensors with slightly different specifications. For example:
- Sony sensors might have a diagonal size of 6.3mm, while
- An OmniVision sensor of the same format might be closer to 6.0mm, and
- ON Semiconductor may use a different pixel pitch or active area altogether.
These seemingly minor details can impact critical design metrics such as distortion correction, chromatic aberration control, and flatness of the field.
By specifying the actual sensor model and manufacturer during the early stages of lens design, we can optimize every parameter—from back focal length to off-axis MTF (Modulation Transfer Function)—to ensure your final system delivers top-tier performance.
The Westech Optical Perspective
At Westech Optical, we approach lens design with a holistic view. Our engineering team collaborates closely with sensor data sheets, manufacturer data, and client requirements to ensure that:
• The image circle perfectly matches the sensor’s active area.
• The MTF complements the pixel size for maximum performance.
• The field of view is accurate to your intended application.
Skipping this step can lead to subpar imaging, requiring refits, wasted budget, and lost time in downstream testing and calibration.
In precision optics, small oversights can lead to major performance issues. That’s why we strongly recommend locking in the specific sensor model and manufacturer before starting any custom lens design. It’s not just a specification—it’s the foundation of every successful imaging system we build.
Thinking about your next imaging project? Let’s align your lens with your sensor from day one.
Contact Westech Optical to discuss your project needs.