B+W Filters 67mm Warming Conversion 81A Glass Screw In Filter
The color temperature of the illumination and the type of film being used are not always properly matched. This is particularly troublesome with color transparency films. This problem can be solved with correction filters in different strengths that can be selected specifically to meet the respective need. Conversion filters make color films designed for use in daylight suitable for use in artificial light.
Conversely, different conversion filters are required for use outdoors in daylight of films designed for artificial light illumination. Light balancing filters provide finer color corrections and filters with the "color correction" designation permit subtle or strong effects on the color rendition of a film.
Color conversion filters balance the spectral composition of the photographic light source to the temperature balance of photographic films. This color temperature is expressed in degrees Kelvin ("K"). High color temperature light becomes blue while low tends to have a reddish tone. Depending upon the degree of necessary color temperature conversion, reddish to brown or blue-toned, color conversion filters in varying density are required to absorb the predominant color tones of the light.
The 81A Filter warms the image from 3400 K to 3200 K.
