The Formatt 4 x 4" 82B Filter is a light balancing filter used to increase the color temperature slightly for a cooler tone. This blue filter absorbs the excessive yellow-red light from daylight in the morning.
There is much flattering light to be found in the early morning and afternoon hours. With sunlight low on the horizon, the red-orange end of the spectrum becomes enhanced. With daylight balanced film, images shot in this light may prove to be a bit on the warm side. The photographer may desire this effect or choose to "cool" things down.
An 82B has a greater "cooling" effect than an 82A. The 82 series of blue filters allows the photographer to keep skin tones somewhat normal by increasing the color temperature to a more daylight balanced level.
