This 77mm 81A Warming Conversion Filter from B+W has an effect similar to that of the Kodak Wratten 81A gelatin filter. It is also similar to the KR1.5 (Skylight) conversion filter except that it is less reddish as it absorbs a little bit of the red.

The 81A controls the bluish coloration that affects daylight film. It can also remove excessive blue from the effects of electronic flash. Good for general scenics when the photographer wishes to remove the bluish cast from open shade or just add warmth to the photograph.

It's Autumn. The clouds are low hanging and the sky is "patchy blue". You've gone for a ride upstate to the mountains and the light in open shade is bluish. A photo taken of your girlfriend with daylight balanced film leaning against the side of a barn will yield bluish tones that she might not find particularly flattering.

An 81A filter will replace some of the yellow missing from the image and bring her skin tones back to a more appealing level. The 81 series (81A, B, C, D and EF) allows you to choose how much warmth you wish to replace in the image.

In production, the filter glass is dropped into the empty filter ring from the rear and held in place with a threaded retaining ring; this is a definite advantage over a competitor who uses a spring clip to hold the glass in place. A threaded retaining ring will hold the glass firmly and securely in place to avoid the possibility of rattling and provide perfect parallelity and        flatness to your front lens element for ideal optics. The part about additional filters not binding is due to the fact that brass is a very stable metal and does not contract or expand like alloy.

The filter ring is made from brass yielding a stronger product. Brass filter rings are also less prone to jamming. In addition, the seal between the glass and filter ring is exceptionally strong giving the filter added strength and durability. The excellent Schott Glass used in the manufacturing of this filter is legendary and synonymous with the highest standards of filter production. 

Benefits