B + W 77mm Infrared Filter # 093 (87C/RG830)
B & W offers three filters for infrared photography, each with its' own unique features.
• This dark red filter is primarily for black and white infrared films.
•It filters out light below 650 nm.
• With color infrared film it produces pictures of a pure red image while making good use of the relatively low sensitivity of infrared films.
• Filter factor is approx. 20 - 40.
• This black infrared filter will filter out the entire visible spectrum.
• It is used with black and white infrared films with a sensitivity up to 1000nm.
• Filter factor is determined by the film sensitivity.
• This orange colored filter blocks the blue and blue-green portion of the visible spectrum up to 500 nm.
• It reduces the excessive sensitivity of color infrared films in this spectral range, separates colors more evenly thereby avoiding a blue tint.
• Filter factor depends upon the film's sensitivity.