What UV Filters to Get

To each their own, of course, I mean anecdotal or not I don't need to run tests to see flare like that. And I never had peace of mind from a filter other than feeling like I could clean it more aggressively.

Also keep in mind the issue of sensor size -- small sensors (incl full frame) need their capture area enlarged 8-fold just to produce a 4x6 print. This means that even if you have a tremendous quality lens, like some of these 80 lpm Zeiss lenses, you're diluting that fine detail to 10 lpm in an 8x enlargement, and the human eye resolves 10-15 lpm. So even if a test only shows that a filter reduces your lens resolution from 60 lpm to 50 lpm, you multiply that degradation for every degree of enlargement, and eventually you get to the point where your detail density is below the resolving power of your eye. That's when you can see it.

DrPablo wrote in post #2021882
To each their own, of course, I mean anecdotal or not I don't need to run tests to see flare like that. And I never had peace of mind from a filter other than feeling like I could clean it more aggressively.

Also keep in mind the issue of sensor size -- small sensors (incl full frame) need their capture area enlarged 8-fold just to produce a 4x6 print. This means that even if you have a tremendous quality lens, like some of these 80 lpm Zeiss lenses, you're diluting that fine detail to 10 lpm in an 8x enlargement, and the human eye resolves 10-15 lpm. So even if a test only shows that a filter reduces your lens resolution from 60 lpm to 50 lpm, you multiply that degradation for every degree of enlargement, and eventually you get to the point where your detail density is below the resolving power of your eye. That's when you can see it.

But what degradation?

No loss of sharpness was detectable. In fact the statistical variation showed the lens + filter to be slightly sharper.

This is the problem. Assumptions are made about an effect without evidence.

If there is evidence please do bring it forward, my own testing certainly does not show the sort of level of degradation that urban myth tells of.

If I thought for moment filters were having a measurable detrimental effect I would question using them. None was detectable. In fact the statistical variation showed the lens + filter to be slightly sharper.

These tests are not hard to do, I recommend everyone tries them before the come to a conclusion.

Lester Wareham wrote in post #2021929
But what degradation?

No loss of sharpness was detectable. In fact the statistical variation showed the lens + filter to be slightly sharper.

This is the problem. Assumptions are made about an effect without evidence.

If there is evidence please do bring it forward, my own testing certainly does not show the sort of level of degradation that urban myth tells of.

If I thought for moment filters were having a measurable detrimental effect I would question using them. None was detectable. In fact the statistical variation showed the lens + filter to be slightly sharper.

These tests are not hard to do, I recommend everyone tries them before the come to a conclusion.

Your tests are what they are, and that's fine, but naturally my own experience is a more important determinant of my behavior (and for what it's worth insight). I wasn't even specifically looking for image degradation -- it found me.

DrPablo wrote in post #2022010
Your tests are what they are, and that's fine, but naturally my own experience is a more important determinant of my behavior (and for what it's worth insight). I wasn't even specifically looking for image degradation -- it found me.

Of course you are entitled to your opinion and I respect that.

But with all due respect I don’t think what you have shown in this thread is evidence that the filter caused the issue.

It has generated your belief that the filter is responsible, but it is not evidence in scientific terms. It maybe you are right, but it is not proven.

I would welcome proof however. This would need to be a comparative shot with and without the filter. As I say easy to do if you put 30 mins aside.

I purchase some B+W from maxsaver.net after a great deal of research into the company and the filters. Great price.

As for the use fo a UV filter as a protective device I only use it when I need it. Outside under windy conditions where dust is blowing alll over I always use a filter. Inside where there is little possibility of direct front contact I use no filter. I have noticed that indoors when I use the UV filter I have more issues with autofocus.

Lester Wareham wrote in post #2021881
One thing I am sure about, no mater how much evidence there is either way, few will change their filter using habits. The debate has been running for at least 20 years that I know of and will probably go on for plenty of time yet.

Twenty? Niepce and Daguerre used to argue about this in the Paris bistros!

DrPablo wrote in post #2021818
Finally, I'd mention that I bought lenses with good image quality for a reason -- and there is a reason there isn't a red stripe around UV filters.

All very good points and for the most part, all agreeable.

Though in concern with this, keep in mind that "a red stripe" is a Canon thing. Just because a filter doesn't have one, doesn't mean that the glass isn't as good - or better - than what's in the lens itself. For example, Heliopan and B+W both use Schott glass. This is of at least as good a quality as that inside your striped lens. Of course it won't compare to flourite or other exotic glass but then you only have one or two of these elements out of potentially a dozen in there anyway and are a different story (apples to oranges).

Heck, for me it's a cost issue. The protection afforded in non blowing debris situations is minimal even with a filter. Anything that would generally scratch the lens would be protected by the hood. If for some reason something came along to smash the front element, the filter isn't going to stop it, it's just going to shatter and send glass fragments into your front element.

For the microscopic amount of protection it provides, it's not worth purchasing a filter for every lens I own. I own two, a 77mm and a 62mm, which will fit all my lenses with step up rings for the 50mm and the 80-200L. They are used when blowing debris is present, about the only time a filter will actually protect the lens. Why spend an extra $200 on filters for virtually no extra protection, and the added bonus of image degradation in certain (not all) situations? When I get more lenses, I won't need to buy more UV filters...but if I constantly used one, I would. That's an extra $100 per lens for virtually no protection. Just not worth it.