A machine vision system may use an 850 nm or 940 nm LED, a monochrome camera with good near-infrared sensitivity, and stable exposure settings—yet still produce images whose contrast changes with factory lighting, sunlight, or reflections from nearby equipment. The problem is often not the…

Edge steepness describes how quickly an optical filter transitions between its passband and its blocking region. It is measured as the wavelength interval between two defined reference points on the transition — for example between the 50% transmission point and the wavelength where transmission drops…

Protected aluminum and enhanced aluminum start from the same vacuum-deposited aluminum film. The difference is what goes on top: protected aluminum adds a single dielectric overcoat that stops oxidation and makes the surface cleanable, with almost no change to the reflectance curve, while enhanced aluminum…

Choosing a narrow bandpass filter manufacturer comes down to three questions: can their coating process hold your center wavelength tolerance across the full clear aperture, do they measure the filter under your actual angle and cone conditions, and is the blocking specification real across your…

Searching for a custom optics manufacturer in China usually means the optical function is already known, a drawing exists, or a prototype needs to be converted into a repeatable production component. The difficult part is not finding a company that can make a lens, filter,…

To choose an optical filter for machine vision, start from the illumination spectrum rather than the filter catalog. Match the filter passband to the light your system actually uses, then verify that the passband still lines up once you account for the range of angles…

Telecentric F-Theta Lens vs Standard F-Theta Lens: Engineering Differences and Selection A telecentric F-theta lens vs standard F-theta lens comparison is mainly a question of beam geometry at the workpiece. Both lens types can be designed for a substantially flat scanning field and approximately linear…

F-theta distortion and field curvature are both field-dependent errors in a laser scan lens, but they fail in completely different ways. F-theta distortion is a position error: the focused spot lands somewhere other than where the scan angle says it should, while staying sharp. Field…

In an f-theta scanning system, spot size and input beam diameter are inversely related: double the collimated beam diameter at the lens, and the focused spot diameter halves. That single relationship is the reason a beam expander sits between almost every laser and every galvanometer…

A fluorescence filter set is three components engineered as one spectral system: an excitation filter (exciter) that cleans up the illumination, a dichroic beamsplitter that separates excitation from emission, and an emission filter (emitter) that passes fluorescence and rejects everything else. Fluorescence filter set design…

The central difference in an aspheric lens vs spherical lens comparison is surface geometry. A spherical surface has a constant radius of curvature, while an aspheric surface deliberately changes curvature from its optical axis toward its edge. That extra design freedom can reduce spherical aberration…

The practical difference in an achromatic lens vs singlet lens comparison is wavelength control. A singlet uses one optical element and is usually adequate for monochromatic light, modest numerical aperture, or applications with relaxed imaging requirements. An achromatic lens normally combines two elements with different…