How a configurable combination of sensors, filters, and optics can help engineers refine a multispectral imaging system before production.
Developing a multispectral imaging system starts with identifying the wavelengths that provide useful information about the target. The objective may be to distinguish between materials, reveal a surface condition, improve contrast during inspection, or identify a chemical or biological feature.
The required wavelengths cannot be considered in isolation. Sensor response, filter bandwidth, optical throughput, resolution, frame rate, lens selection, illumination, and operating conditions all affect the result. The most suitable combination is often determined only after testing representative samples.
SpectroCam 2™ provides a configurable platform for testing these choices during product development. Users can select the camera, sensor, filters, and lens for the application, then evaluate and refine the configuration as testing progresses. Torrent Photonics can carry the confirmed spectral configuration into a customized OEM system.
Initial wavelength choices may be based on published research, material data, previous measurements, or early laboratory results. Testing under realistic conditions can show that the original configuration needs to change.
A selected band may not provide enough contrast between similar materials. A narrower filter may improve spectral selectivity while reducing the signal reaching the sensor. Accessing UV or NIR wavelengths may require a different detector, and a change in resolution can affect the available frame rate.
The application introduces further variables. Illumination, motion, working distance, temperature, background materials, and ambient light can influence image quality, and measurement repeatability. Developers may also find that a laboratory configuration is too large, slow, or complex for the final product.
A platform with a fixed sensor and filter set limits how these factors can be investigated. A configurable setup allows alternative sensor, filter, and optical configurations to be evaluated before the system architecture is finalized.
SpectroCam 2™ was designed for product development, proof-of-concept testing, research, and OEM integration. Its architecture allows the principal imaging components to be selected according to project requirements.
Camera options span UV, visible and NIR wavelengths. Developers can balance spectral response, resolution, frame rate, and field of view instead of working around a single camera specification.
SpectroCam 2™ accepts a wide range of lenses, with a Nikon mount available off the shelf. Lens selection can be considered alongside the sensor and filter configuration during system development.
Its portable format supports laboratory and field evaluation, as well as integration into larger equipment. The same development platform can therefore be used for initial spectral tests and later system-level trials.
SpectroCam 2™ uses an eight-position rotating filter wheel fitted with user-swappable, high-performance hard-coated interference filters. Each position can contain a filter selected for a specific spectral band. As the wheel rotates, the camera records images through the individual filters for subsequent analysis.
Filters can be exchanged as project requirements change. Engineers can compare center wavelengths and bandwidths without purchasing a different camera platform. This is useful when the most informative bands are not known at the start of the project.
An initial filter set might cover several candidate wavelength regions. Testing may show that some bands add little information, while others require a different center wavelength or bandwidth. Individual filters can then be updated and evaluated within the same platform, helping developers identify which spectral bands provide the most useful information for the application.
The sensor must provide sufficient response at the wavelengths transmitted by the filters while meeting the resolution, noise, exposure time, and imaging speed requirements of the system.
A silicon sensor may be suitable for visible and part of the near-infrared range but will not cover much of the SWIR. A SWIR sensor reaches longer wavelengths, although resolution, pixel size, frame rate, and cost can differ significantly from visible camera options.
Filter bandwidth also affects the amount of light reaching the detector. Narrow bands can improve spectral discrimination but may require longer exposure times or controlled illumination. Wider bands provide more signal but may include wavelengths that reduce contrast between the features being examined.
SpectroCam 2™ allows sensor and filter selections to be evaluated together, helping developers verify that spectral performance can be achieved within the practical constraints of the application.
Standard bandpass filters may be suitable for early tests or applications that use established spectral bands. Other projects require a filter designed around a particular material response, illumination source, detector, or measurement method.
Torrent Photonics can design and manufacture custom hard-coated interference filters in-house using optical coating and photolithography. Specifications can be developed around center wavelength, bandwidth, transmission, blocking range, and physical dimensions.
If testing identifies a more effective band, a filter can be produced for that requirement and installed in the existing wheel. Filters selected during spectral evaluation can then inform the application-specific OEM design.
Fixed-filter cameras, tunable filters, and filter-wheel systems each have different advantages.
The best choice depends on the stage of development and the imaging requirements. Fixed-filter cameras are often appropriate once the required spectral bands have been confirmed and the system configuration is unlikely to change. Tunable filters can be useful when many wavelength bands must be evaluated without physically changing filters. Filter-wheel systems are often preferred during development because individual bands can be selected, compared, and replaced as testing identifies the most effective spectral configuration.
A fixed-filter camera can provide a compact, application-specific solution once the required bands have been confirmed. Its configuration may offer limited scope for change during development.
Liquid crystal tunable filters provide electronic wavelength selection and can be useful when an application requires many closely spaced measurements. Optical throughput, tuning range, and available bandwidth depend on the technology and operating wavelength.
SpectroCam 2™ uses independently specified interference filters. The center wavelength, bandwidth, transmission, and blocking performance of each band can be selected separately. Hard-coated filters can also provide higher optical throughput than many LCTF-based approaches.
The user-swappable wheel is particularly useful when a development team needs to compare candidate bands or revise the configuration before committing to the final system. The appropriate architecture will still depend on the number of bands, spectral spacing, imaging speed, and operating environment required by the application.
Sensor, filters, optics, illumination, software, and mechanical design all affect the performance of a multispectral imaging product.
A practical development program can be organized into five stages:
SpectroCam 2™ supports the testing and refinement stages within a common platform. Once the configuration has been established, Torrent Photonics can provide optical and mechanical customization, filter manufacturing, systems development, assembly, and production.
The data gathered during proof-of-concept work can define the sensor, filters, optics, and performance specifications used in the OEM design. This reduces the risk of committing to a fixed architecture before spectral requirements have been validated during development testing.
SpectroCam 2™ supports development across machine vision, industrial inspection, scientific imaging, environmental monitoring, agriculture, authentication, forensics, security, defense, surveillance, and life science research. The optimal configuration will depend on the target feature, wavelength range, operating conditions, and imaging requirements.
Applications may include material identification, contamination detection, surface inspection, vegetation analysis, water monitoring, document examination, and research involving UV, visible or NIR wavelengths. Filter selection, sensor response, and illumination requirements should be evaluated for the specific application.
Performance claims should be assessed for the specific target and operating conditions. Torrent Photonics can review the wavelength range, sensor response, filter specification, optics, and mechanical requirements before recommending an approach.
Each spectral band must contribute useful information to the required detection, measurement, or classification task. Additional bands are valuable only when they improve the result, and the sensor and optics must capture them with sufficient signal and spatial performance.
SpectroCam 2™ supports multispectral system development before the final system architecture is established. Torrent Photonics can then carry the selected configuration into custom filter manufacturing, OEM development, and production.
Share your target wavelengths, samples, imaging requirements, and development objectives. Torrent Photonics can help evaluate sensor options, filter specifications, optical requirements, and potential system architectures for your application.