This Dark Orange filter darkens blue, violet, green and yellow-green.nnThis filter is made of glass and measures 100 x 100 mm (4x4") x 4 mm thick.nnnFeatures:nn- Particularly useful for any landscape and architectural photography (on black and white film) requiring sharp outlinesnnn- The sky will be distinctly tinted with clearly contrasting cloudsnnnSpecifications:nn- Type: Dark Orangen- Size: 4x4" (100 x 100 mm)n- Grade: 21n- Filter Factor: 4 (+2 stops)n- Effect: Absorbs blue and blue-greens; Makes blue tones darker as in marine scenesnnn- Application: Suitable for landscapes and nature scenesn- Construction: Glass