Machine Vision Components

Machine Vision Cameras, Lenses and Lighting

The three basic components of an inspection station. We work out the resolution, field of view and lighting from your defects and cycle time, then propose and quote a camera, lens and lighting combination. Country of origin: Taiwan.

中文

Illustration of machine vision components: an industrial camera with a fixed-focal lens, a ring light and a bar light — Original illustration, not a product photo. Actual appearance varies by model.

Items

Item	Types	What to check first
Industrial cameras	Area scan or line scan; monochrome or color; global or rolling shutter	Resolution and pixel size, frame rate, interface (GigE Vision, USB3 Vision, CoaXPress, Camera Link)
Lenses	Fixed focal length, telecentric and line-scan lenses	Focal length and working distance, image circle covering the sensor diagonal, resolving power, depth of field
Lighting	Ring, coaxial, backlight, bar and dome lights	Part surface (reflective, transparent, textured), wavelength, strobe and trigger synchronization

Basic layout of an inspection station (3D illustration, not to scale). Selection order: smallest defect and cycle time, then resolution and field of view, then focal length and working distance, then lighting method and wavelength. The field of view follows from sensor size, focal length and working distance; the lighting method depends on the part surface (reflective, transparent or textured). How to work out the focal length is explained in our article on lens focal length.

Selection methods are explained in our articles on five questions before adopting AOI and calculating focal length. If you are not sure the inspection is feasible, start with the Machine Vision Feasibility Test.

Selection calculator

From defect size to camera, focal length, depth of field and exposure

Enter the field of view, working distance, smallest defect and conveyor speed. The calculator follows the method in our lens focal length article and the industrial automation page.

Sensor (nominal size: pixels, pixel pitch)

Field of view (width) mm

Working distance (lens front to part) mm

Smallest defect to detect mm

Aperture

Conveyor speed (0 if the part stops) mm/s

Resolution

Size of one pixel
Smallest defect covers

Lens

Magnification m
Ideal focal length
Nearest standard focal length
Actual field of view with it
Working distance for the exact field of view

Depth of field, diffraction and exposure

Depth of field (approx.)
Diffraction blur (Airy disk)
Maximum exposure (blur within 1 pixel)
GigE transfer per image (8-bit mono)

Magnification m = sensor width (pixels × pixel pitch) ÷ field of view; focal length f = working distance × m ÷ (1 + m); the nearest of the standard focal lengths 8, 12, 16, 25, 35, 50 and 75 mm is chosen, and the actual field of view = sensor width × (working distance − f) ÷ f. Depth of field ≈ 2N·c·(1 + m) ÷ m² with the circle of confusion c taken as two pixel pitches; Airy disk diameter = 2.44 × 0.55 µm × N; maximum exposure = pixel size ÷ speed; GigE assumes 1 Gb/s at about 90 % efficiency. See our lens focal length article and section 3 of industrial automation integration; working distance is measured from the lens front, so confirm it with the lens data or by test.

Send these results with a quote request Start with a feasibility test on your samples