Neutral Density (ND) Filters from Shape Optics Technologies Pte Ltd are engineered to reduce light intensity without altering color balance. By providing spectrally neutral attenuation, these filters enable accurate exposure control and signal optimization across imaging and measurement systems.
SOT ND filters are available in multiple optical densities and form factors, allowing precise control of light levels for research instruments, cameras, sensors, and industrial optics. Advanced coating techniques ensure high optical clarity, excellent durability, and stable performance under demanding operating conditions.
Key Features
- Precise Light Attenuation – Uniform, consistent reduction of light intensity
- Wide OD Selection – Optical densities from OD 0.3 to OD 3.0
- Flat Spectral Response – Nearly constant transmittance across broad wavelengths with minimal color shift
- High Durability – Designed for harsh environments and long service life
- Versatile Applications – Photography, optical testing, medical imaging, and industrial systems
Spectrum Transmission
ND filters provide consistent attenuation across the spectrum, making them ideal for applications requiring accurate light control over a wide wavelength range.
If standard components do not meet your needs, custom ND filters can be designed for specific wavelength bands and transmittance targets.
Coating Quality & Environmental Reliability
All ND filters are qualified to stringent standards:
- Adhesion Test (MIL-C-675C) – No blistering or peeling after repeated tape removal
- Thermal Cycling – −62 °C to +71 °C with no coating detachment
- Abrasion Resistance (MIL-C-675C / CCC-C-440) – No surface damage after 25 cycles at 1.0 lb load
- Humidity Test – 95–100% RH at 49 °C for 24 h without defects
- Solvent Resistance – Stable after acetone and alcohol exposure
- Salt Spray Test – 100 h at 35 °C, 5% salt concentration with no degradation
Standard Specifications
| Model | Cut-on Wavelength (nm) | Transmittance | Wavelength Range (nm) | Optical Density |
|---|---|---|---|---|
| NH-LP335 | 335 ± 5 | T ≥ 90% | 340–500 | OD ≥ 3 @ 200–320 |
| NH-LP400 | 400 ± 5 | T ≥ 90% | 410–1100 | OD ≥ 3 @ 350–380 |
| NH-LP410 | 410 ± 5 | T ≥ 90% | 420–1100 | OD ≥ 3 @ 350–390 |
| NH-LP420 | 420 ± 5 | T ≥ 90% | 430–1100 | OD ≥ 3 @ 350–410 |
| NH-LP430 | 430 ± 5 | T ≥ 90% | 440–1100 | OD ≥ 3 @ 350–420 |
Additional models and custom specifications are available upon request.
Typical Applications
- Photography & Imaging – Prevent overexposure; enable long exposure control
- Optical Instruments – Light level management in spectrometers and sensors
- Industrial Systems – Cameras and inspection optics requiring stable attenuation
- Medical Imaging – Regulating illumination in diagnostic equipment
- Laser Power Control – Fine adjustment of beam intensity for measurement