need advice for UV filters

[mendel_leisk]

<p>I use B+W MRC on almost all my lens, but happen to start out with a Hoya SMC on my Canon 24-70.</p>

[peter_j2]

<p>My best UV filter is the Sigma DG 58mm Multi-Coated UV Filter which is on my Canon EF 50mm f/1.4 USM lens. </p>

<p>The next best would be the B+W 77mm MRC UV Filter which is on my Canon EF 70-200mm f/4L IS USM lens.</p>

<p>Last would be the Nikon 77mm L37C Multi-Layered Coated UV Filter which is on my Canon EF 17-40mm f/4L USM lens. I don't like this filter because the front coating will spot and sometimes smear over time. The one that did smear, Nikon replaced under warranty.</p>

<p>I would buy the Sigma because it is also about $10 cheaper than the B+W.</p>

[arash khoshghadam]

<p>It is a good idea to use a UV filter in front of the lens to prevent accidental scratches though using such a filter increases the possibility of flare. I always use a Hama UV infront of all my lenses spacially my 60mm macro. it is a good one and has served me for years. It has no effect on exposure metering.</p>