These filters possess level spectral transmittance characteristics in the visible region and attenuate light by absorption with minimal reflection. Typically, neutrality and density of absorptive filters are a function of the material and the thickness. Since Hoya neutral density filters are held to a specific optical density, the thickness is only a function of the glass type. They are useful in light control applications for measuring instruments and exposure control in imaging. Spectral variations occur as optical density increases.
Specifications
Material: | NG1, NG4, NG9, or NG11 |
Wavelength range: | 400-700nm |
Size: | +/-0.20mm |
Thickness: | +/-0.5mm |
Clear aperture: | >80% of dimension |
Parallelism: | < 3 arc minutes |
Surface quality: | 80-50 scratch and dig |
Flatness: | < 1λ, subject to the size |
OD tolerance: | +/-5% |
Coating: | AR coating |
These filters possess level spectral transmittance characteristics in the visible region and attenuate light by absorption with minimal reflection. Typically, neutrality and density of absorptive filters are a function of the material and the thickness. Since Hoya neutral density filters are held to a specific optical density, the thickness is only a function of the glass type. They are useful in light control applications for measuring instruments and exposure control in imaging. Spectral variations occur as optical density increases.
![](\"/userimg/10751/Neutral-density-filter1.jpg\"/)
Specifications
Material: | NG1, NG4, NG9, or NG11 |
Wavelength range: | 400-700nm |
Size: | +/-0.20mm |
Thickness: | +/-0.5mm |
Clear aperture: | >80% of dimension |
Parallelism: | < 3 arc minutes |
Surface quality: | 80-50 scratch and dig |
Flatness: | < 1λ, subject to the size |
OD tolerance: | +/-5% |
Coating: | AR coating |
