I have a Nikkor 55-200mm and just got a 52mm polarizing filter. Why won't it mount on?

I was told to buy the same size that it says on the end of the lens. I also have a 18-55mm lens, it won't fit.

Have you tried screwing it onto the end of the lens using the threads?

Both of those lenses take 52mm filters so you should not have issues with that polarizing filter fitting on them.

Assuming that it is a circular polarizing filter, you need to make sure you are holding the stationary ring as well as the rotating filter element when you try to attach it to your lens. If you just hold onto the part that rotates, it will keep spinning without threading onto the lens. You should be turning the filter clockwise once you have the threads aligned.

If you're sure you've been trying to put the filter on correctly so far, you should inspect the treads on your lenses and the filter to make sure they are not damaged.

1) take off the lens hood.

2) Polarizing filters rotate, you need to hold both parts while you try to screw it on.

3) If it's a cheap one off ebay, it will probably wreak the filter thread on the end of your lens if you try too hard to fit it!