Bayonet Mounted Filters
Another type of common filter system is the bayonet mounted style. With a bayonet mount you just line the filter up with the appropriate markings on the lens and then twist it on until it locks itself into place. It's just like a short snapping motion.
A bayonet style filter works the same as a screw on filter as it is also a piece of glass or plastic that is held inside a ring. The only difference really is the mounting attachment.
Many medium format cameras lenses and assorted video cameras use bayonet filters. Bayonet filters are common, but are mainly used for older style or specific makes of cameras. Bayonet mounted filters can range in price from about $10 to $800.