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Knight Optical(UK) Ltd - - +44 (0)1622 859444

Wratten longpass filters

What are you looking for in Stock?

The colour effects within Wratten colour filters are achieved using organic dyes in a gelatine material, which is not possible in colour glass. This filter type can be manufactured to as little as 0.1mm thick and are more accurately controlled and documented. The below listed optical stock are band-pass type Wratten colour filters.

Wratten filters were originally designed for use in photography but are also used in imaging applications from industrial manufacture to medical.

Whilst less robust than polyester filter, their spectral data is more accurately documented. Wratten gelatin filters are now being replaced by Wratten 2 type filters which are manufactured using a ridged polymer. Wratten 2 filters are more robust and unaffected by water and moisture as gelatine type.

For more information on our stock range of Wratten 2 filters or to enquire about a custom quotation, please contact our technical sales team.

Dimensions: 75 x 75 x 0.1mm

Wavelength cut-on listed in table is transition cut-on wavelength (T=Tmax/2)
Wavelength cut-off listed in table is transition cut-off wavelength (T=Tmax/2)
Wavelength peak is centre wavelength 

  • Large 300x100mm sheets available that can be cut to smaller shapes and sizes.
  • Stock sheets can be CNC machined to unusual shapes.
  • Coating options from antireflective to anti-scratch.
  • Mounting options.

Stock Optics

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Part No. Wavelength cut-on (nm)Wavelength cut-off (nm)Wratten No.ColourLength
411FWP7575 Download 41126972BYellow (UV Absorbing)75750.1 £40.85
430FWP7575 Download 43027152EYellow (UV Absorbing)75750.1 £40.85
494FWP7575 Download 49426988Yellow75750.1 £40.85
528FWP7575 Download 528269415Yellow75750.1 £40.85
540FWP7575 Download 540271216Yellow/Orange75750.1 £40.85
600FWP7575 Download 600271525Tricolour Red75750.1 £40.85
717FWP7575 Download 717271889BBlack (Absorbs Visible Passes IR up to 2500nm)75750.1 £90.25
794FWP7575 Download 794271487Black (Absorbs Visible Passes IR up to 2500nm)75750.1 £90.25
519FWP7575 519269612Yellow75750.1 £40.85
852FWP7575 Download 852271687CBlack (Absorbs Visible Passes IR up to 2500nm)75750.1 £90.25

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Get in touch

Our Multi-Lingual Sales Team are here to help with your requirments:

UK +44 (0)1622 859444
UK +44 (0)1622 850614
UK +44 (0)1622 851078
+1 401 583 7846

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