[BigMackCam]

After finding that one of my filters (a "Kenko *Digital Filter MC UV") had a pretty severe optical flaw that was affecting image quality, I started looking for reviews on various well-known UV filters. There are quite a few articles and posts on various websites and forums, but I came across one in particular that I liked. They compared 16 different UV filters from a variety of manufacturers, looking at instrument-based measurements for light transmission and real-world testing on susceptibility to flare, vignetting etc. I'd like to have seen some analysis - even subjectively, with the naked eye - on resolution / sharpness of the general image with each filter, but otherwise it's a very useful set of tests, with some surprising results.

For those who dislike the use of UV filters, or who may have read the reviews before, please disregard

Here's the article: UV filters test

[schnitzer79]

good stuff!! thanks a lot!

[Zav]

The only problem with this article is that it has not been updated. For example, since the publication of the article, Hoya has released its HD products line.

[redcat]

yeah, an interesting article, very useful. I bought my filter base on this ^^

[BigMackCam]

The only problem with this article is that it has not been updated. For example, since the publication of the article, Hoya has released its HD products line.

Yes, I realise it's a little stale by now, but most of the filters listed are still widely available, so I still think it's pretty useful

[Lowell Goudge]

I found that the best way to test uv filters is to point lenses with them mounted at a bright light source off axis, and then look at the reflections in the image compared to the native lens.

The mor reflections added the poorer the filter.

I found this out shooting at night with my legacy lenses, and went through a bunch of UV / skylight filters I had that fit my super tak 50/1.4. (Element version) Filters ranged from Hoya, to canon, to Nikon, to several local brands, and an SMC Pentax filter. The canon and Nikon filters were no better than the cheap store brands, but the SMC Pentax was actually quite good

But the cleanest results were with no filter, so I have been systematically taking filters off all my legacy lenses

[BigMackCam]

I found that the best way to test uv filters is to point lenses with them mounted at a bright light source off axis, and then look at the reflections in the image compared to the native lens.
...
...
But the cleanest results were with no filter, so I have been systematically taking filters off all my legacy lenses

That's one of the tests used in the review article I refer to. It's amazing just how many flare / ghost artefacts some of the filters produce. But some of the filters - like the Hoya HMC and more expensive B+W models - seem to do a very good job indeed (though none as good as no filter at all).

Since I'm a confirmed UV filter fan (purely for lens protection), I can live with the small risk of minor flare / ghosting the Hoya HMC filters are reported to offer. In any case, I intend to try them out

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Last edited by BigMackCam; 05-13-2015 at 07:52 AM.

[Lowell Goudge]

That's one of the tests used in the review article I refer to. It's amazing just how many flare / ghost artefacts some of the filters produce. But some of the filters - like the Hoya HMC and more expensive B+W models - seem to do a very good job indeed (though none as good as no filter at all).

Since I'm a confirmed UV filter fan (purely for lens protection), I can live with the small risk of minor flare / ghosting the Hoya HMC filters are reported to offer. In any case, I intend to try them out

The issue of protection vs flare is a real tough one, I am looking at using filters or not on about 40 legacy lenses, some Pentax/takumar and some third party. Quality filters often cost more than the lenses,mbut the lenses might be hard to replace in some instances, so it is a real mixed bag. For the moment, since I like to use legacy MF stuff for night shots, I am gradually pulling the filters

[BigMackCam]

The issue of protection vs flare is a real tough one, I am looking at using filters or not on about 40 legacy lenses, some Pentax/takumar and some third party. Quality filters often cost more than the lenses,mbut the lenses might be hard to replace in some instances, so it is a real mixed bag. For the moment, since I like to use legacy MF stuff for night shots, I am gradually pulling the filters

Although I don't have quite the collection you do, I'm in a similar position. I have numerous older Pentax & 3rd party lenses that were very inexpensive. They give me a lot of enjoyment, but I don't have the appetite to spend a great deal of money on lens protectors. For those lenses, I'll be quite happy with protective filters that don't conspicuously impact the colour rendition, resolution and contrast under "normal" shooting conditions, with the expectation that I'll temporarily remove the filters when shooting at night, toward the sun, or otherwise in the presence of bright light sources. For my DAs - particularly the Limiteds - I'd be prepared to spend more on better quality filters... but, I suspect I'll still end up removing them where bright lighting within the FOV is involved, so I'm not sure that a significant additional investment on the filters is warranted so long as basic IQ is unaffected. I've ordered one of the Hoya HMC UV filters in 49mm to try on my Pentax M and DA Limited lenses, and may also try one of the B+W models on my Limiteds to see if there's an improvement over the Hoya...

[Volker76]

*shrug* uv filters are a ripoff anyway. *shrug*

[BigMackCam]

*shrug* uv filters are a ripoff anyway. *shrug*

That depends entirely on what you want and expect from them. Mine have served me very well, with only a couple of exceptions

[fourkids]

*shrug* uv filters are a ripoff anyway. *shrug*

Well, I used to be an advocate of filter-a-waste. But after a shoot in the beach when the wind blew the sand like crazy (the hood was on and I did my best to prevent the lens from facing the wind), I noticed my DA*60-250 acquired a few small but legible scratches on the front element. I recanted and joined the dark side of filter manufacturers henceforth.

[pentaxus]

Something not mentioned in the filter test is that a filter can degrade image sharpness. Years ago when I worked at a camera store and had appropriate test equipment we had a customer angry about the piece of junk Pentax 50mm 1.7 he bought from us. I checked it out and wondered how it got out of the factory. Then I noticed the filter on the lens and took it off. All of a sudden the lens was sharp and didn't focus past infinity. Also, like Lowell, I found the Pentax brand filters to be outstanding.

[BigMackCam]

Something not mentioned in the filter test is that a filter can degrade image sharpness. Years ago when I worked at a camera store and had appropriate test equipment we had a customer angry about the piece of junk Pentax 50mm 1.7 he bought from us. I checked it out and wondered how it got out of the factory. Then I noticed the filter on the lens and took it off. All of a sudden the lens was sharp and didn't focus past infinity. Also, like Lowell, I found the Pentax brand filters to be outstanding.

Ha ha

Yes, I did mention in my original post that this aspect was missing in the reviews. The only filter I've had obvious IQ problems with was the Kenko I posted about recently, but I have other Kenko filters that don't exhibit the problem, so I guess it was a defect in the glass or coatings that affected my faulty one.

Interestingly, I bought an old 28mm lens cheaply on flea-bay recently that someone had allegedly used on a Pentax digital body. When it arrived, it had a "CPC Phase 2 1A" haze filter fitted. I tried it out on my K3 and all of the images had a pink-ish cast to them... Took the filter off, and everything was fine - quite a nice bit of glass, actually, with good colour rendition I'll bet there's many a lens gets returned, retired or sold because the owner didn't consider that the filter was the cause of poor images!

[rawr]

Filters vs non-filters - a perennial topic.

I remember putting this illustration together in 2010, based on the same Lenstip article.



Nowadays I only use UV or other filters if I need them - which turns out to be vary rarely. For physical protection indoors and out, I get by with hoods and careful lens handling.