UV Filter Questions

I've been wrestling with the idea of purchasing some UV filters for my lenses (17-40/4, 24-105/4, and 70-200/4) but apart from sticking with the quality brands (Hoya, B+W, etc) and going with something that is multicoated I am still a bit intimidated by which particular brand and type (thin or normal?) to go for.

Now my current body is an XTi so I'm not sure how that plays into my decision but I did a search a while ago and noticed a few people had mentioned that thin filters should be used for wide angle lenses when used on FF cameras. I plan to eventually go FF in the future so could someone please clarify if I would need to go with a thin filter or not for my 17-40/4? Also, if I go with a thin filter does that mean it won't have any front threads to attach a lens cap? Ideally I'd like to be able to attach a lens cap on top of all of my filters.

Lastly, I kind of have my eye on Hoya Pro1-D HMC filters as well as B+W MRC filters. The latter being slightly more expensive. Could someone with experience with these filters vouch for their quality for me? Are they compatible with a 17-40/4 when used with a FF camera? Do they allow a lens cap to be attached? Is it worth it to pay more for the B+W filters?

Thanks in advance.

Why? If you're thinking about using them for protecting the front element of the lens, don't bother. You'll get just as much, if not more, protection from a good, dedicated lens hood and you'll get the added benefit of flare reduction and better contrast from stray light being prevented from entering the lens. In some situations, having a UV filter on your lens will cause unwanted reflections in the image. Another reason not to use UV filter is unwanted vignetting at wider focal lengths on some lenses and cameras. This is made worse if you stack filters, such as adding a polarizer on top of the UV filter.

Speaking of polarizers, your money would be better spent investing in good quality circular polarizers for your lenses. Polarizers can add contrast to clouds and blue skies, reduce reflection in shiny surfaces and act as a neutral density filter in a pinch.

I don't have the 17-40; my Sigma 15-30 doesn't take front filters so I can't answer to whether you'd need a thin or regular UV. I would suggest a thin circular polarizer however. I do use B+W MRC UV on all my other lenses; contrary to many people's belief, lens hoods are of only limited value against many hazards. They'll stop things from coming in from the side, but aren't much protection against wind-blown debris, branches and twigs when you're going through undergrowth or unmaintained trails, or if small children or animals get inquisitive with fingers or noses. I'm often in areas where propwash, jetwash, or high winds are active, with attendant flying grit, sand, silt, etc. Lens hoods don't do anything to protect against that (including the unexpected gust in otherwise mild conditions). They're also essential to maintaining the weather seal in weather-resistant L lenses, and if you're in salt-spray areas. I haven't yet seen evidence that a good-quality filter (both the Hoya Pro-1 and B+W MRC, as well as Heliopan's SH-PMC, are good-quality) will degrade IQ, although there's plenty of evidence, both anecdotal and through tests, that lesser-quality filters can. Further, it's difficult to attach and/or remove a lens cap when a hood's in place, so there's always that interval between removing the cap and ataching the hood when things are exposed. And if you're in a hurry, that time could be unduly prolonged as you drop the lens back into your bag.

B+W thin polarizers currently don't have threads on the front, so they're restricted to press-on caps. For that you want the Hoya Pro-1. As I only have polarizers on when I'm using them and in that case there's also a lens hood in place (making lens cap use problematic), I continue to use B+W CPs, even the thin ones, but YMMV.

I always use my lens hoods and yes, if I do end up getting some UV filters I'll be getting them for protective purposes and I intend to use them with my lens hoods. I know that lens hoods provide protection but I still can't help but think that a perfectly placed stray elbow in a crowd or some rogue tree branch could still do some damage to the front element of my lenses. And yes, I understand the importance of circular polarizers and already have a 77mm one for my 17-40 and 24-105 but still need to get one for my 70-200.

I guess I'm just asking photographers out there who have experience using UV filters for their opinion. Are high quality UV filters worth it for protective purposes? It seems like they should be since the high quality ones don't affect IQ and offer a bit of security in case something happens.

Must have posted at the same time. I'm firmly in the "pro filter" camp. There was a poll on here a year or two ago; the results showed that more people used filter+hood; fewer used one or the other, and a reckless few used neither. But more people used filter with or without hood than used hood without filter.

Jon wrote in post #3058869
B+W thin polarizers currently don't have threads on the front, so they're restricted to press-on caps. For that you want the Hoya Pro-1. As I only have polarizers on when I'm using them and in that case there's also a lens hood in place (making lens cap use problematic), I continue to use B+W CPs, even the thin ones, but YMMV.

Thanks, Jon. I've got a question for you, though.

Are you strictly talking about circular polarizers here or are you talking about UV filters as well? Sorry if this is a dumb question, I just want to be sure I understand all of this correctly and which specific filters are capable of having a lens cap put on and which are not.

The UV filters I'm currently looking at are the Hoya Pro1-D HMC filters and the B+W MRC filters.

Thanks

Alright I've clarified that the B+W MRC filters I'm looking at are the regular type.

According to this page (http://www.the-digital-picture.com …im-UV-Filter-Review.aspx), though, it says that lenses with a FOV of 28mm or wider should use thin filters. Is this true? Or can I get away with using a regular UV B+W MRC filter with a 17-40 on a FF camera?

I quit using UV filters back in the early '80's because of vignetting with wide angle lenses. In the ensuing 25 years, I have never encountered a situation where a filter would have protected the lens when a hood wouldn't have. If a blow to a lens is hard enough to fracture a hood, then no filter on earth is going to save the lens.