Adaptor-rings are available in various diameters, and this is the first step in determining which system you should use. First, look at all your lenses and refer to the largest diameter lens in your collection. The lens diameter is either written on the front or side of the lens itself, in the cap, or in the lens user's manual. Once you know what diameter your lens is, refer to the chart below to chose the system that will fit your needs.

C Compatible with CREATIVE filter-holder
E Compatible with EVO filter holder
* If used with a wide-angle lens of this diameter, Cokin advises upgrading to a bigger system to prevent vignetting issues that may occur.
(FF) If used with a lens under 28mm on a full frame, you may need to remove one or two slots from the filter-holder to prevent vignetting, or to upgrade to a bigger system.