The B+W 30.5mm #25 Red (090) Filter is a basic contrast filter, primarily for use with black and white film. This red filter dramatically darkens skies, cuts through haze, and increases overall contrast. When compared to the orange #22 filter, the #25 produces very dark, almost black skies and a surreal contrast between foliage, clouds, and sky. There is an 8x filter factor with this filter, requiring an increase of 3 stops for normal exposure.
B+W filters are constructed from high quality Schott glass for increased optical clarity and color fidelity. They feature a brass filter ring for durability as well as jamming prevention.
| Type | Red |
| Size | 30.5 mm |
| Grade | #25 (090) |
| Filter Factor | 8 (3 stops) |
| Effect | Dramatically darkens skies, increase in overall contrast |
| Construction | Schott glass |
| Front Filter Thread Size | 30.5 mm |
| Front Lens Cap Size | 30.5 mm |