This is the P164 Circular Polariser Glass Filter from Cokin . It fits in the optional Cokin P Holder. Light rays which are reflected become polarised. Polarising filters are used to select which light rays enter your camera lens. A polariser helps make a blue sky bluer as well as making clouds stand out. It can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colours providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies according to how the filter is rotated and its orientation to the sun.
Specifications
| Filter Type | Circular Polariser |
| Filter Factor | 2.3 - 2.8 (1.2 - 1.5 Stop) |
| Shape | Rectangle |
| Circular Size | 84 mm |
| Rotating | Yes |
| Cokin Compatibility | Cokin P |
| Front Accessory Thread / Bayonet | Unthreaded |
| Filter Material | Glass |
| Coatings | None |
