Optical Filters for Embedded Machine Vision
Bandpass, IR cut, and dualband day/night filters engineered for CMOS sensors. Integrate directly with M12 lenses for compact camera modules.
From single-wavelength bandpass filters to dual bandpass day/night solutions, our optical filters provide spectral control for embedded vision. Available with M12 lens bonding services for turnkey camera module integration.
Understanding Optical Filter Types
Essential definitions for selecting the right filter for your machine vision application
Bandpass Filter
Transmits a specific wavelength range while blocking all others. Defined by center wavelength (CWL) and bandwidth (FWHM). Essential for isolating LED or laser illumination in machine vision to maximize signal-to-noise ratio.
- • Typical FWHM: 10-50nm
- • Blocking: OD4+ (99.99%)
- • Applications: Inspection, barcode reading
IR Cut Filter
Blocks infrared wavelengths above ~650nm to produce accurate color reproduction matching human vision. Prevents IR light from desaturating colors on CMOS sensors that are inherently IR-sensitive.
- • Cut-off: 650nm typical
- • High visible light transmission
- • Applications: Color cameras, RGB imaging
Dualband / Day-Night Filter
Dual bandpass filter transmitting visible (400-700nm) and NIR (typically 850nm or 940nm) bands simultaneously. Eliminates mechanical IR cut switchers for 24/7 surveillance with automatic day/night transition.
- • Dual passband architecture
- • No moving parts required
- • Applications: Surveillance, automotive ADAS
Longpass Filter
Transmits wavelengths above a specified cut-on point while blocking shorter wavelengths. Used for NIR imaging, fluorescence applications, and blocking visible light for covert illumination systems.
- • Cut-on wavelengths: 700-1000nm
- • Sharp edge transition
- • Applications: NIR vision, covert surveillance
Shortpass Filter
Transmits wavelengths below a specified cut-off point while blocking longer wavelengths. Blocks IR contamination in visible imaging or isolates UV/blue wavelengths for specialized inspection applications.
- • Cut-off wavelengths: 400-700nm
- • Heat rejection capability
- • Applications: UV inspection, heat blocking
Neutral Density (ND) Filter
Reduces light intensity uniformly across all wavelengths without affecting color balance. Used to prevent sensor saturation in high-brightness conditions or extend exposure times for motion blur applications.
- • Optical density: ND2 to ND1000
- • Spectrally neutral response
- • Applications: Outdoor cameras, welding inspection
Shop Optical Filters
Bandpass, IR cut, dualband, and specialty filters for embedded vision applications
Filter Transmittance Data
Measured spectral response curves for Commonlands optical filters. Click to download the complete dataset.
Spectral transmittance curves for bandpass and dualband filters. Click image or button below to download Excel data.
Dualband vs Regular Optical Filters
Understanding when to use dual bandpass day/night filters versus standard IR cut filters
| Characteristic | Regular IR Cut Filter | Dualband Day/Night Filter |
|---|---|---|
| Daytime Operation | Blocks all IR for accurate color imaging | Passes visible band for color imaging |
| Nighttime Operation | Requires mechanical removal of filter (ICR switcher) | Passes NIR band (850nm or 940nm) simultaneously |
| Moving Parts | Yes - IR cut filter switcher required | None - fully solid-state operation |
| System Complexity | Higher - motor driver, mechanical assembly | Lower - single fixed filter element |
| Failure Modes | Motor failure, mechanical wear, stuck filter | Minimal - no moving components |
| Color Accuracy | Excellent - full IR blocking during day | Good - slight NIR leakage in visible band |
| Cost | Filter low cost, but ICR switcher adds expense | Higher filter cost, lower total system cost |
| Best Applications | Color-critical imaging, studio cameras | 24/7 surveillance, automotive, outdoor IoT |
Optical Filter + M12 Lens Integration
Eliminate separate filter holders by bonding optical filters directly to M12 lens assemblies. Our cleanroom filter bonding service creates compact, sealed optical modules for embedded vision applications where space and reliability are critical.
Filter-lens integration prevents dust contamination, ensures optical alignment, and simplifies camera module assembly. Available for prototype through volume manufacturing with 100% optical testing.
Filter Gluing Service Pricing
$100 one-time NRE + per-unit bonding fee. Add filters and lenses to cart, then add the gluing service for your quantity.
Add Filter Gluing Service to Cart →Need Mechanical Day/Night Switching?
For applications requiring complete IR blocking during daytime, we also offer mechanical IR cut filter switchers (ICR) that physically move the filter in and out of the optical path.
Browse IR Cut Switchers & Accessories →
Custom Optical Filters for Volume Projects
Need a specific center wavelength, bandwidth, or form factor not in our standard catalog? Commonlands offers custom optical filter manufacturing for projects exceeding 1,000 pieces. Our coating partners can develop custom spectral profiles to match your exact requirements.
Custom Wavelengths
- • Specific center wavelength (CWL)
- • Custom bandwidth (FWHM)
- • Multi-band passband profiles
- • Application-matched spectral curves
Custom Form Factors
- • Non-standard diameters
- • Square or rectangular shapes
- • Custom thickness requirements
- • Integrated mounting features
Integration Services
- • Filter-to-lens bonding
- • Camera module assembly
- • Custom packaging
- • Traceability documentation
NRE & Minimum Order Quantities
Custom optical filter development requires non-recurring engineering (NRE) fees to cover coating design, test runs, and spectral verification. NRE is typically quoted based on complexity and is often credited against production orders. Minimum order quantities for custom filters start at 1,000 pieces. Contact our engineering team for a detailed quote.
How to Select the Right Optical Filter
Choosing the optimal optical filter requires understanding your application's spectral requirements, environmental conditions, and integration constraints. This engineering guide covers the key selection criteria for machine vision and embedded camera applications.
Application-Based Selection
- Color Imaging (RGB Cameras) Use IR cut filters with 650nm cut-on to block near-infrared light that desaturates colors. CMOS sensors are inherently IR-sensitive, so IR blocking is essential for accurate color reproduction matching human perception.
- Machine Vision with LED/Laser Illumination Select bandpass filters matching your illumination wavelength (typically 850nm, 940nm for NIR or visible wavelengths for color LED). Narrow FWHM (10-25nm) maximizes contrast by rejecting ambient light while passing structured illumination.
- 24/7 Surveillance Systems Dualband day/night filters enable seamless transition between visible daytime imaging and NIR nighttime operation without mechanical IR cut switchers. Choose 850nm passband for visible glow illumination or 940nm for covert applications.
- NIR-Only Imaging Longpass filters (780nm+ cut-on) block visible light for covert surveillance, agricultural imaging (NDVI), or silicon wafer inspection where NIR penetration is required.
Technical Specifications to Consider
- Center Wavelength (CWL) & Bandwidth (FWHM) For bandpass filters, CWL should match your illumination source within ±5nm. FWHM determines selectivity—narrower bandwidth provides better ambient rejection but requires precise wavelength matching. Typical machine vision FWHM ranges from 10nm (narrow) to 50nm (wide).
- Optical Density (OD) & Blocking OD4 (99.99% blocking) is standard for machine vision. Higher OD needed for applications with strong out-of-band signals. Verify blocking across your sensor's full spectral sensitivity range, not just visible wavelengths.
- Angle of Incidence (AOI) Interference filters blue-shift at off-axis angles. For wide-angle lenses (>60° FOV), consider specialized wide-angle interference coatings to maintain consistent spectral response across the field of view.
- Physical Dimensions & Mounting Filter diameter must exceed your lens clear aperture. For M12 lens integration, typical filter sizes are 4.5mm to 8mm diameter. Verify thickness compatibility with available back focal distance in your optical stack.
Optical Filter Applications
Optimized filter solutions for every embedded vision vertical
Surveillance & Security
24/7 monitoring with seamless day-to-night transition
- • Dualband day/night filters
- • IR cut filters for daytime color
- • 850nm/940nm bandpass for NIR illumination
Mobile Robotik
Structured light and SLAM-optimized filtering
- • Narrow bandpass for laser line detection
- • IR cut for RGB-D cameras
- • Wide-angle compatible coatings
Automotive ADAS
Driver monitoring and surround view systems
- • 940nm bandpass for covert DMS
- • Dualband for parking cameras
- • High-temperature rated substrates
Maschinelles Sehen
Industrial inspection and quality control
- • LED wavelength-matched bandpass
- • Low-distortion filter substrates
- • High transmission interference coatings
Robotik aus der Luft
UAV payload and agricultural imaging
- • NDVI filters for vegetation analysis
- • Lightweight filter substrates
- • Multi-spectral filter sets
Intelligenter Einzelhandel
Intelligent checkout and inventory tracking
- • IR cut for accurate color rendering
- • Anti-reflection coated filters
- • Compact M12 lens integration
Optical Filter Technical FAQ
Common questions from embedded vision engineers
Request Custom Filter Quote
Connect with our California-based engineering team for custom wavelengths and filter-lens integration
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