Tiffen 58mm 12 Filter (Yellow)
The #12 Yellow Filter from Tiffen is a filter designed to increase contrast and tonal separation for black and white photography. The filter absorbs blue colors, rendering blues darker. Haze is minimized for aerial photography and excessive blue is removed for astrophotography. The #12 Yellow Filter is recommended as a basic filter for use with Kodak's Aero Ektachrome Infrared Film. The filter has a filter factor of 2, so you must increase by 1 full stop to your exposure to compensate.
Tiffen filters are not dyed, but are manufactured by using ColorCore technology. This process laminates the filter material between two pieces of optical glass and grinds down and polishes the glass. The glass is then mounted to the metal ring, which after that can be screwed onto the lens for the desired effect.
Builds contrast in B&W images Haze is eliminated for aerial photography Absorbs blue colors ColorCore technology

Tiffen 58mm 25 Filter (Red)
Filters for black and white photography perform a variety of filtration effects including contrast control, enhanced skin tones, tonal corrections and more dramatic landscapes. Although originally intended for use with black and white film, this filter can also be used as a creative tool in color imaging. Create dramatic sky effects, emphasizing cloud contrast for landscapes. Simulate a moonlit scene at midday with slight underexposure. Use with infrared film to yield extreme contrast with skies, turn foliage white and cut through fog and haze.