Infrared filter

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An infrared filter is a filter to remove visible light and only pass infrared light in different wavelengths. These are mainly used in infrared photography.

[edit] Filter products

• The Kodak Wratten 87, 87A, 87B, 87C
  • Inexpensive gelatine filter.
  • 87A and 87B are no longer produced.
  • 87 starting at 750nm, 87C at 800nm, 87B at 850nm, 87A at 950nm

• The Hoya R72
  • High quality filter starting at 720nm, which includes some visible light.

• The Hoya RM90
  • High quality filter starting at 900nm

• The Hoya RM100
  • High quality filter starting at 1000nm

• The M&K 1000
  • High quality filter starting at 1000nm

• The M&K 093 and 095
  • starting at 830nm

• The Home Made Filter
  • Exposed and developed camera film often works as a cheap infrared filter. The home-made filter typically begins transmission at around 710-730nm.[1]
  • "Congo Blue" theater gels are designed to pass IR light in order to avoid damage from heating. When combined with red filters which block their visible blue, the combination is reported to pass the shorter wavelengths of infrared up to around 720nm. [2]
  • A piece of double-side polished silicon works as an infrared filter with a relatively sharp cutoff of about 1050nm