B+W Filtro de Vidro Warming Color Conversion de Cor 30,5mm 81B

This 30.5mm 81B Warming Color Conversion Filter from B+W is an excellent choice when you want to produce more pleasing skin tones - especially on cloudy or overcast days. It is similar to a KR-3 (81C) conversion filter but with an effect that is not as pronounced. This filter can also be used with electronic flash to remove some of the blue tint that may occasionally be produced in strobe photography when the color temperature is above 6000K.

The reputation of B+W's Schott glass is world renowned. The high production standards combined with a sturdy brass filter ring make B+W filters hard to beat. These filters have a "heft" to them that is impressive. They may feel heavier but the benefit is in the construction and results. Not only is the glass exceptional but so is the seal between the ring and glass. Schott Glass used in the manufacture of this filter is legendary and synonymous with the highest standards of filter production. It comes with a solid 10-year warranty.

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This filter uses B+W's standard F-Pro mount which is nowthinner than their previous filter mounts. It is thin enough to be used with 24mm lenses on a full frame body without the irritating effects of vignetting (the darkening of the image corners due to the filter ring intruding into the frame). F-Pro's also have an updated filter retaining ring that now holds the glass in from the back. The advantage here is that if your filter should get screwed on too tight, when twisted off, the ring is no longer in danger of being damaged.

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.

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.