Hi Bill, Lester is correct you need a step down ring as they are called, but you have to get one that is 48mm.
The filter threads are exactly 48mm, if you camera lens is 49mm, or 52mm, and so on you can order them.
I have a number of these, such as 49mm to 48mm, 55mm to48mm and so on.
all camera shops can order them from Hoya Filters, they are readily available.
Cheers Leon