| Sensor Format | 1/3 in: approximately 4.8 × 3.6 mm 1/1.8 in: approximately 7.2 × 5.4 mm 2/3 in: approximately 8.8 × 6.6 mm 1 in: approximately 13.2 × 8.8 mm | The sensor format determines the minimum lens image circle and affects the achievable field of view with a given focal length. | Choose a lens rated for the same format or a larger format. A lens designed for a smaller sensor may cause dark corners or vignetting. |
| Lens Mount Compatibility | Common industrial mounts include C-mount and CS-mount. C-mount flange focal distance: 17.526 mm. CS-mount flange focal distance: 12.5 mm. | The mount must match the camera body, and the flange distance must allow the lens to focus correctly. | Do not attach a CS-mount lens directly to a C-mount camera without the correct spacing. A C-mount lens may be used on some CS-mount cameras with an appropriate 5 mm spacer, subject to the camera design. |
| Lens Image Circle | The lens image circle should be equal to or larger than the sensor diagonal. Approximate sensor diagonals: 1/3 in = 6.0 mm; 1/1.8 in = 9.0 mm; 2/3 in = 11.0 mm; 1 in = 15.9 mm. | An insufficient image circle produces vignetting, uneven illumination, and reduced usable image area. | Allow a small margin above the sensor diagonal, especially when the lens is used with an adjustable aperture, close focus, or off-axis illumination. |
| Focal Length and Field of View | Approximate object width: FOV = (Object Distance × Sensor Width) ÷ Focal Length Use consistent units for all measurements. | Focal length controls how much of the target is visible at a defined working distance. Longer focal lengths provide a narrower view. | Measure the required object width and working distance first, then select a focal length that provides the required coverage without excessive digital cropping. |
| Field-of-View Example | A 1 in sensor with a 13.2 mm horizontal width, a 16 mm lens, and a 400 mm working distance gives an approximate horizontal FOV of 330 mm. | A worked estimate helps verify whether the selected camera and lens can cover the complete inspection area. | Allow additional margin for part-position variation, mechanical tolerances, and any region that must be inspected around the target. |
| Resolution and Pixel Coverage | If a 2,000-pixel-wide image covers a 200 mm-wide object, the sampling is approximately 0.10 mm per pixel. | Pixel coverage determines whether small defects, edges, characters, or measurement features can be separated reliably. | Define the smallest feature to detect and provide multiple pixels across it. The required number depends on contrast, optics, focus, and inspection algorithms. |
| Lighting Geometry | Common arrangements: diffuse dome lighting for reflective or curved surfaces; coaxial lighting for flat reflective surfaces; backlighting for silhouettes and dimensional inspection; low-angle lighting for surface texture and scratches. | Lighting direction and diffusion often have a greater effect on inspection reliability than camera resolution alone. | Select the lighting method according to surface finish, defect type, geometry, and required contrast. Use controlled, repeatable illumination rather than relying on ambient light. |
| Exposure and Motion Control | For moving objects, short exposure times reduce motion blur. Pulsed LED lighting can provide high peak brightness for brief exposures while limiting average heat and power. | Motion blur can hide small defects even when the image has sufficient nominal resolution. | Check camera triggering, exposure control, light pulse duration, and the object's speed as one system. Avoid increasing gain as the primary solution for insufficient illumination. |
| Aperture and Depth of Field | A smaller aperture, represented by a higher f-number, generally increases depth of field but reduces the amount of light reaching the sensor. | Parts with height variation may not remain sharp across the entire inspection region at a wide aperture. | Balance depth of field against diffraction, exposure time, and available lighting. Lock the aperture after setup to prevent image-to-image variation. |
| Spectral Requirements | Visible lighting is commonly used for general inspection. Red or near-infrared illumination can improve contrast for selected materials, while ultraviolet requires suitable optics and sensor response. | Different wavelengths interact differently with coatings, inks, plastics, metals, and biological or chemical residues. | Confirm sensor sensitivity, lens transmission, filter compatibility, and operator safety before selecting non-visible illumination. |
| Working Distance and Mechanical Space | Working distance is the distance from the specified lens reference point to the inspected object. Lens specifications may also list a minimum object distance for focusing. | The available installation space may restrict focal length, lighting position, cable routing, and protective housing dimensions. | Verify the real mounting envelope, minimum focus distance, lens barrel clearance, and lighting access before finalizing the camera position. |
| Industrial Environment | Relevant conditions may include dust, moisture, vibration, temperature variation, cleaning fluids, and electromagnetic interference. | Environmental factors can change focus, reduce contrast, damage equipment, or introduce unstable image output. | Specify suitable enclosure protection, lens protection, vibration support, thermal management, and cable shielding for the installation site. |
| Recommended Verification Test | Test the complete camera, lens, lighting, trigger, and processing configuration using production parts and the actual mounting distance. | Specification sheets cannot fully predict glare, reflections, vibration, part variation, or algorithm performance in a real production environment. | Validate FOV, sharpness, illumination uniformity, exposure stability, defect contrast, repeatability, and cycle time before deployment. |