Filter for EF 17-40 f4 L

[natio]

Since you're using a crop body, vignetting should not be a problem. A Hoya HMC UV filter is good enough.

[evenfy]

Since you're using a crop body, vignetting should not be a problem. A Hoya HMC UV filter is good enough.

As I mentioned earlier, I'm upgrading to FF within about 6 months, so really don't want to have to buy a new one then 

On that note; please, PLEASE let there be a 5D tomorrow!

[D.Sim]

To be honest all reputable manufacturers have their own version of a high quality, slim filter... Hoya, B+W, they all work well. . I have Hoya on all of my L's for protection, and they only come off if I want to use a ND/Circ Polarizer - I use Marumi for those. no complaints.

[marekjoz]

In this configuration you can only consider SLIM filters.

Below you'll find the effect you achieve when usimg Marumi Circular-P.L on 17-40 with 5d2 (most probably without even stacking with Sigma DG UV but not sure and can check if you wish).

Photos:
1. Original
2. Cropped to avoid this vignetting (effective ca 17-18MP after crop)
3. 100% original image (must open for full image) of the corners.

As you can see on FF with such a wide lens you must have thin filters. Marumi is not thin at all, it's rather thick in fact and on 17-40 you loose some mm from wide side. On the other hand it's also not easy to shoot with polarizer such wide angles because of it's irregular behaviour in such a case.

[evenfy]

Small update amidst the 5DIII coverage; I bought the B & W XS-PRO from maxsaver.net. Excellent service, 25 % lower price than B & H, and free wordwide shipping (based in Hong Kong). Read some independent reviews beforehand, and people seem to be very satisfied.

[nitsujwalker]

I use a B&W F-Pro on mine and I love it.  It cleans extremely easily and doesn't cause much extra flare.  I don't know what your price range is... I purchased mine for $88 I think.  I hear some of the upper-end Hoyas are good too.