A:Answer The lens hood is a three-piece unit: the hood adapter, a locking ring, and the hood itself. The hood adapter should thread into the outer end of the filter if the filter itself is threaded. It should be unless you have an oddball mounting system. The hood locks into the adapter. I have UV filters that are more than 30 years old and the threaded into my modern Canon lenses and accepted the hood adapter just fine. Be careful not to cross thread the adapter; the filter's threads are metal and those of the adapter are plastic.
