This red filter is ideal for significantly improving contrast as it completely absorbs green and blue whilst enhancing red. In addition to contrast control, red filters enhance skin tones, tonal corrections and are effective for more dramatic landscapes.nnThis filter is in glass and measures 100 x 100 mm (4x4") x 4 mm thick.nnnFeatures:nn- Clouds are significantly enhanced, almost to a stormy atmosphere; Darkens blue sky creating dramatic contrast between sky and cloudsn- It is most effective for cutting through haze, and moonlight effects are easily achieved; Creates greater contrast between foliage and flowersn- It is also suitable for infrared photographynnnSpecifications:nn- Type: Redn- Size: 4x4" (100x 100)n- Grade: 25n- Filter factor: 3 (+2 stops)n- Effect: Completely absorbs green and blue and enhances redn- Application: Create dramatic sky effects, enhance cloud contrast for landscapes; Simulate a moonlit scene in broad daylight with slight underexposure; Use with infrared film to achieve extreme contrast with skies, render foliage white and cut through fog and hazen- Construction: Glass