Frequently Asked Questions

Glass ND filters are more robust and tend to have more uniform absorption characteristics than gelatine ND filters. Both attenuate light by absorption, but care must be taken to avoid overheating with both types.

The FNG4050 Absorptive Glass Neutral Density Filter is used to attenuate light by absorption in applications such as spectroscopy, machine vision, ellipsometry, and photography.

Yes, Knight Optical offers an extensive custom optic service and can supply ND filters cut to sizes and shapes to fit individual applications and mount filters where applicable.

The FNG4050 Absorptive Glass Neutral Density Filter is available in 12.5mm and 25mm diameters, and 50x50mm squares.

The FNG4050 Absorptive Glass Neutral Density Filter is available with blocking between 0.1 and 4.0 OD.

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