By far the most important accessory you can buy for your professional camera lens is a high-quality filter. B+W filters are valued by professional photographers for their exquisite optical quality and fine multicoating. B+W is a must have for every pro quality lens.
This dark red filter (092) is for black and white infrared films and filters at light below approximately 650nm. It allows pictures of a pure red image while making good use of the relatively low sensitivity of infrared films. Filter factor is approx. 20-40. The not-so-strong infrared filter does not block the complete visible light spectrum and enables recording with visible and invisible IR components. The black and white contrasts are not as high as the (093) filters but still effective.
Green leaves and grasses are reproduced from bright to white. A "wood effect" with dramatic contrast between clouds and sky can be achieved.
Tip: Infrared photography is not a substitute for Thermal Photography. Thermal photography also captures images from infrared radiation, but uses a much higher range of about 10,000 nanometers and above.