Cokin Center Spot Filters are have a clear center spot which isolates and draws attention to your subject, surrounded by neutral (colorless) diffusers. They come in small center spot (060 series) which is designed for lenses between 50 & 135mm, and large center spot (070 series) which are for lenses between 21 & 35mm. A060 Diffuser 1 is a mild, diffuser for a gentle effect. (Available as 070 for 21-35mm lenses). A061 Diffuser 2 is stronger than diffuser #1. (Available as 071 for 21-35mm lenses). A060/A070 is also available in an oval design which is ideal for horizontal or group portraits (Filter A 140); suitable for all focal lengths.