Filter for 20mm?

Any suggestions on good UV filter (mainly for lens protection) for 20/1.7?

Thanks.
Sagar

Yes, the B&W UV filter. See here what it looks like http://www.mainlinephoto.com.au/prod52.htm , but you probably can get it somewhere else (maybe b&hvideo?...). The only caveat is that it adds to the thickness of the lens by virtue of it being there. What I mean is that I never noticed having an UV filter on bigger lenses, but on the 20mm pancake - because it is so thin - you do notice the filter when it's on. I guess it's the price to pay if you want protection for the lens.

There might be also so-called "slim" versions of UV filters for 46mm thread, but the question is whether you can then fit the cap on, because obviously there's less for the cap to grab onto, so I don't know if it works (or even if a slim 46mm UV filter exists...).

Main point, though, is to stick with good brands that have quality glass (B&W being one of them), otherwise you might compromise image quality of the lens. With the 46mm thread, your choice of brands is more limited. Or, to be more correct, your choice of quality UV filters is more limited, even within a brand that has some good products within its range. For example, Hoya make a 46mm UV filter, but not in their Pro1 or new Digital range, only in their lower-range filters, which I would not get since you can get a B&W for about the same price (and B&W have German Schott glass).

Unfortunately, I beg to differ. The B+W 46mm UV filter is unfortunately NOT multicoated and even though it has an excellent optical quality glass, it does not work well with the 20mm. There is a very pronounced flare/ghosting effect that happens with bright light sources in the frame when you use this filter. I had it on my 20 mm and took it off. B+W does not seem to make a multicoated UV filter in 46mm. Hoya does but I have not tried it yet. A lens shade would probably work as well to protect the lens without adding unnecessary extra glass.

Ermmmm, I think B&W was one of the first companies to bring multi coated filters way back in those dark 20th century ages. My 46mm from the '80s reads: B&W 46 E 010 1x MC Multi Resistant. I've always taken that MC to indicate multicoated...

In line with this topic a question about the B&W 46mm UV-IRcut filter. Exactly when I was about to order it, I read that this has about 30 layers of ultrathin coatings which make it less suitable for WA lenses because light travelling under sharper angles would get blocked more. Anybody have any experience with this type of filter on the 20mm?

I tried the Hoya and on a few photos found the green spots people mentioned. 20mm seems like a no filter lens, except maybe for things like ND and CP filters; but for those I just use them on my 14-45.

b&W has 46 mm uncoated- the regular UV one and also the more
expensive MRC one.

MRC i got is coated.......multi.....

I bough this one.

http://www.bhphotovideo.com/c/product/11985-REG/B_W_66030559_46mm_UV_Haze_010.html

It has the MRC that everyone raves about on here. So far so good. Before that I bought one at the local camera store for like 50 bucks, which I though was steep. It was a Promaster HRC. I returned it to save a couple bucks and to find out what the big deal with the B+W filters are.

The only difference that I noticed is that you couldn't tell that the Promaster filter was on the camera. The B+W is like a tank in comparison. It is large, the threads stick out further, there is writing all over it "Made in Germany," "46mm," "B+W." Of course there are other factors, like the B+W is supposed to be easier to clean.

Who knows. The UV filter topic is a hot one on these forums. Most people would tell you to just forget about it. I go to the beach alot though. When I got back last time there was some dried sea spray on the element. Dried sea spray is basically just salt crystals. I figured I should get some kind of protection.