OK, I'm still on my quest for a 77mm polarising/polarizing (depending on which part of the world you are in) filter, which I intend to use on both my Tokina 12-24 and my Canon 70-200IS. This is where I'm "at":
I have discovered the possibility of requiring a "slim" filter to prevent vignetting (sp??) on the Tokina.
I have heard that most slim filters do not have a front thread and therefore require a (supplied) slip on lens cap, which has a tendency to fall off.
I have read a few people's opinions that with the 1.6 crop factor of the Rebel XT, I won't have a problem with a normal filter.
I haven't been able to find anyone who has actually tried a normal filter on a Tokina 12-24. If there's anyone out there who has, please speak up.
Finally, I just discovered the "Moose filter", made by Hoya.
http://www.moosepeterson.com/gear/moosefilter.html![]()
He claims that his filter doesn't cause vignetting on ultra-wide lenses and it has a front thread. I could not find a reference to whether or not they are multicoated. I realise they are also a warming filter- that would be a nice bonus, although I am aware it can be achieved in Photoshop. This is the only polarising filter I've been able to find that is specifically for UWA lenses, that also has a front thread.
Does anyone have any experience with these filters?
Or alternatively, do you have other suggestions?

