Neutral-density
Filter Sets |
| |
| When it is necessary to control
the intensity level of the light, these filters will attenuate a
beam with very little effect on the spectral content. Two types
are in common use: absorbing glass filters and reflective metallic
coated filters. The metallic coated filters are more spectrally
neutral where-as the absorbing glass filters may be combined additively. |
Specifications |
Surface Flatness |
2 per 25mm |
Deviation Allowed From Catalog Nominal Density at 550nm:
K0.02 density for densities of less than 0.5; K5% of
density value at or above density 0.5 Accuracy of Spectrophotometer
Curves Between 200nm and 700nm: K1% of full scale
|
Clear Apertures |
23mm and 48*48mm |
Dimensions |
K0.2mm |
Thickness |
2.0 mm |
Parallelism |
3 arc minutes |
Substrates Material |
BK7 grade A fine Annealed
or optical quality synthetic fused silica |
Cosmetic Surface Quality |
Pitch-polished, 80-50
scratch and dig
Coating Vacuum-deposited metallic alloy
|
Coating |
Vacuum-deposited metallic
alloy |
|
Neutral-density Filter Sets