Polarizer sized...? now I am lost please help

[lbowman920]

I got my DSLR (Canon Rebel XT) about 4 days ago and since then have been reading this forum and reading understanding exposure. So I know I am going to need to get a polorizer and I k now I need a circular one so when I went to B&H to look at them I noticed sizes besides them like 58mm circular polarizer - so now I am lost what does the size corospond to and how do I know which one I need

 

[Big Mike]

Filters usually screw into the front of the lens with threads. So the filter has to match the size of the threads on the front of the lens.

If you look at the front of your lens, you will see a diameter printed on it. That is the size of filter that you need.

If you have the EF-S 18-55mm lens, I believe the thread size is 58mm.

If you have more than one lens (or plan to have more) you don't need to buy different filters for all of them. You can buy step-up-rings which act like an adaptor so that you can use a larger filter on a lens with smaller threads.

 

[lbowman920]

Now I get it, Thanks so much