2.5 OD 50mm Square, Reflective ND Filter

Angle of Incidence (°):

Coating:

Surface 1: Inconel

Substrate:

Float Glass

Optical Density OD:

2.5

Reflection (%):

55.00

Dimensions (mm):

50.0 x 50.0

Surface Quality:

80-50

Thickness (mm):

1.60 Nominal

Transmission (%):

0.3

Type:

Neutral Density Filter

Blocking Wavelength Range (nm):

400 - 700

Dimensional Tolerance (mm):

±0.5

Clear Aperture (%):

Neutrality:

±5% of Optical Density

Note:

Optical density values are average over specified blocking wavelength range.

Surface Flatness:

4 - 6λ

Regulatory Compliance

Reach 191:

Compliant

RoHS 2015:

Compliant

Product Family Description

Spectrally Flat
Maximum Accuracy and Neutrality at Moderate Price
Use Stacks to Create Intermediate Density Values

These filters have constant density values across the surface. The transmission to reflection ratio varies with density selection. In stacks, the total density is the sum of each filter’s density. ND filters are used primarily for the attenuation of light over a wide spectral range. They are often used in laser and photometer applications, where excessive power can cause damage or inaccurate results. Orient mirrored side toward source at 0° angle of incidence.

Optical Density exhibits an additive relationship; for example, stacking filters with OD values of 0.6 and 0.9 yields a resultant density of 1.5. The optical density is related to the transmission by the following equation:
T = 10^-OD x 100 = Percent Transmission.

Reflective Neutral Density Filter Kits

Reflective Neutral Density Filter Kits are available with either 8 or 14 optical densities. The kits with 8 filters include our most popular filters, with densities of 0.3, 0.5, 1.0, 1.3, 1.5, 2.0, 2.5, and 3.0. The kits with 14 filters include all available densities, except for 3.0. Kits are ideal for determining precise system optical density requirements. Custom densities are available for OEM applications.