Circular Polarizer

I hope this is going to be my last question about CP's. I am almost ready to make a decision on going with the BW MRC filter BUT, now I am wondering whether I should get the 82 mm for my 16-35 and then get step-up rings for my 72 and 77 mm lens.

The only thing in holding me back in doing so is that I RARELY use the 16-35 mm canon lens, so my thoughts are should I buy for the 77mm and get the step up for the 72 mm.

Also, in using step-up rings does that reduce the quality of the filter or is it best to have filters for every lens?

Which is the best route?

Barbara

I would get the 82mm, and rings for the others, its better to be oversized than undersized. The 82 will fit the 16-35 perfectly, and it will larger than the 77/72mm so you wont have to worry about vingetting. If you can get the slim one, its a bit more but on the 16-32 you will reduce the chance of vingetting.
I dont think you will see any image loss using rings.
I have the Singh Ray LB CPL. Might consider it. Less light loss than the others.

I just bought my 16-35 after getting rid of my 17-40. When faced with the 82mm filter expense I did some research. Marumi Super is the direction I am going. Outperforms almost all other CPs, is thin and has threads in front.

http://lenstip.com …_Results_and_su​mmary.html

I would buy the 82 because it's your biggest lens. You would hate to need it and not have it.

Step-up rings won't affect IQ. But if you don't use the 16-35 much (I assume it's the Mk. II; the original one uses 77 mm filters) I'd probably go with the 77 mm, since the 16-35 at the wide end takes in so much sky that a CPL used to darken the sky would darken only part of the sky. You'd have an intense blue area fading to a washed-out blue as you move toward the sun under those conditions. Personally, I have a filter for every lens though, since I dislike changing filters when I change lenses, and it's even more essential to have a filter for each lens if I'm using multiple bodies in "polarizer" conditions. Looking at your lenses I'd say get, or build up to, at least 2x77 mm, or maybe the 77 and 82 mm, a 72 mm for the 85, and if it's the non-L macro, a 58 mm.

Good point, Didnt think about that. I have the same problem with the 10-22mm

Jon wrote in post #10125275
since the 16-35 at the wide end takes in so much sky that a CPL used to darken the sky would darken only part of the sky. You'd have an intense blue area fading to a washed-out blue as you move toward the sun under those conditions.

I had the same dilemma. I dont really use my 16-35 that much for instances when I might need a CPL BUT I didnt want to not have the option should I ever want to. So, I ended up buying a CPL for BOTH the 82mm and 77mm filter sizes. Im probably going to be getting a 58mm one someday too. I thought and tried the step up/step down rings, but the thing that really bothered me most was that when you do that, you cant use the lenses hood for any of the smaller filter sized lenses because the filter is too big.