You have a polarizing filter for a lens don't you liz, which lens is it for. Maybe you could use a step down ring for it, if the lens you are trying to fit it to is smaller than the filter, I don't do that, but then I have only one and use that on the 28-135 IS lens. I have lost track of your hardware and what lenses you are using now and I know weight is an issue with you which is unfortunate but I can relate to that very easily.