25A / R2 red filter is especially effective for increasing contrast in black & white photography. Ideal for dramatic cloud effects in landscapes, due to it’s blocking of the color blue rendering those areas of the sky darker. It can also be applied creatively in color and infrared photography. Blocks over 90% of the light below 650mn, transmitting only red.
For Color Photography: While this filter was designed for black & white photography, it can be used with color film to produce a specific color effect.