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Glass Neutral density filters

These Glass Neutral Density Filters are an inexpensive form of absorption density filter. They are made using the Schott range of NG glass types.  Neutral density filters attenuate light by absorption whilst achieving minimum reflection. The density of neutrality of the filters is achieved through selection of the filter type and calculation of the thickness. The optical density is reasonably consistent in the visible (400-600nm) but may be higher or lower in the NIR depending on glass type.
 


Only UK and EU customers are charged VAT at 17.5%, customers outside the EU and EU customers based outside the UK who have a valid EU VAT number will not be charged VAT

Bulk Discounts!
Where (B) appears next to a price below, bulk prices are available, click the (B) button to view!


PDFPart No.MaterialThickness (mm)Density @546nmTrans (%) @ 546nm Trans (%) @ 700nmTrans (%) @ 780nmTrans (%) @ 850nm Trans (%) @ 1060nmTrans (%) @ 1500nm PriceQtyBuy
FNG0125
NG11
0.6
0.1
79
80
78
75
69
77
£17.95

FNG0225
NG11
1.4
0.2
63
64
60
54
43
59
£17.95

FNG0325
NG11
2.3
0.3
50
52
46
39
27
44
£17.95

FNG0425
NG11
3.2
0.4
40
42
35
28
17
34
£17.95

FNG0525
NG11
4.1
0.5
32
33
27
20
11
26
£17.95

FNG0625
NG5
2.3
0.6
25
31
30
24
15
32
£17.95

FNG0825
NG5
3.1
0.8
16
21
20
15
8.2
22
£17.95

FNG1025
NG5
3.9
1
10
14
13
9.4
4.3
15
£17.95

FNG1525
NG4
2.9
1.5
3.2
5.3
6.7
4.6
2.7
11
£17.95

FNG2025
NG4
3.8
2
1
2
2.7
1.6
0.79
5.5
£17.95

FNG2525
NG3
2.4
2.5
0.32
1.4
2.5
2.5
1.2
9.8
£17.95

FNG3025
NG3
2.9
3
0.1
0.6
1.2
1.2
0.51
6.2
£17.95

FNG4025
NG3
3.9
4
0.01
0.11
0.29
0.29
0.087
2.5
£17.95

FNG9200
SET OF 13 Filters
NA
NA
NA
NA
NA
NA
NA
NA
£219.00

Specification 
Material:Schott Colour Glass
Optical Density :± 12.5% (@546nm)
Diameter:+0.0 / -0.2 mm
Length / width:± 0.2 mm
Thickness:± 0.1 mm
Surface quality:<60-40
Flatness:<2.5λ over 90% test area
Parallelism:<3 arcmin
  
 

Specific requirements
We can manufacture Schott Colour-glass filters to any size at short notice, so if your requirements are not listed please contact us by telephone / fax or email: stockrequirement@knightoptical.co.uk

Options available
  · AR Coating
  · Cutting down or edged to special shapes and sizes
  · Mounting (circles)

Technical Data Sheets
Set of transmittance curves are available for each filter on request, please specify type.

See also
Metallic neutral density filters
Gelatin neutral density filters

See also
FNG0400 12.5mm dia set (13 filters)
FNG0200 125mm dia set (13 filters)
FNG0300 50 x 50mm set (12 filters)
For storage boxes (see accessories)


  
 
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      Knight Optical (UK) Ltd
      Templetree House, Sandway Road, Harrietsham, Kent ME17 1HT. United Kingdom.
      Phone: +44 (0)1622 859444   Fax: +44 (0)1622 859555
      e-mail: info@knightoptical.co.uk   Web design by Smart ePos