Color Filter Glass : Products & Services

Neutral Density Filters

These filters possess level spectral transmittance characteristics in the visible region, and are numbered with the average value of transmittances at 10nm steps in the 400nm to 700nm range. ND-50, for instance, signifies an average transmittance of 50%.

Since the filters control light intensity without selectively absorbing energies at specific wavelengths, they are ideal for exposure control in color photography, and are also used for light control in various other measuring instruments. Sine neutral density filters exhibit variations in spectral characteristics depending on melting conditions, they are designed to uphold designated performance capabilities through control of the thickness. Polishing tolerances are normally ±0.1 mm, and the lower the transmittance of glass types, the more significant will be the transmittance variations caused by the tolerances.

Employment of adequate types of neutral-density filters and control of their thickness enable formation of combinations of filters with any transmittances that may be desired.

In addition to the products below, other neutral density filters with different optical densities (OD) can be fabricated upon request. Please contact us for more information.
ND-03
ND-13
ND-25
ND-40
ND-50
ND-70
Color Filter Glass : Neutral Density Filter Data
print-friendly data tabledefinition of terms
Item / Filter Type Standard Value Color Specification (Standard illuminants A) Thickness Reflective Index Chemical Properties Thermal Properties Mechanical Properties Specific Gravity
Tav (%) x y mm nd Dw DA Tg TS α -30/70 α 100/300 HK FA S
ND-03 10±2 0.453 0.408 2.5 - 1 3 490 565 60 65 530 100 2.41
ND-13 12.5±2 0.446 0.416 2.5 1.510 1 1 535 595 58 68 530 100 2.43
ND-25 25±2.5 0.447 0.415 2.5 1.507 1 2 535 600 62 66 550 100 2.42
ND-40 40±4 0.449 0.413 2.5 1.504 2 3 525 570 61 65 550 100 2.42
ND-50 50±5 0.445 0.412 2.5 1.504 2 4 495 555 62 66 550 90 2.42
ND-70 70±5 0.449 0.410 2.5 1.500 4 5 470 540 66 72 510 100 2.39
print-friendly data table
Tav (%): Average transmittance at 400~700nm

Note: The listed data are standard value. Because of continuous product improvement, the various data listed are subject to change without notice.