# Image quality with or without filters



## climber (Aug 14, 2014)

I'd like to ask, if anyone here has ever done some kind of test, where the difference in image quality is visible while using UV/clear filters or not. If yes, could you share those test shots to see the difference? Or do you know for that comparison on any other web site?

I'm mainly interested in difference while using the best UV/clear filters like B+W, Hoya, etc.

Thanks


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## LuCoOc (Aug 14, 2014)

As usual Roger over at lensrentals.com did it:

http://www.lensrentals.com/blog/2011/06/good-times-with-bad-filters

http://www.lensrentals.com/blog/2010/12/the-glass-in-front-of-your-glass-all-about-filters


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## climber (Aug 14, 2014)

Thank you for those links. 

But actually, they don't speak how filter affects an image quality or in which cases they have the greatest impact on image quality (flares, contrast, saturation). OK, unless you don't put on 5 filters one on top of the other.


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## neuroanatomist (Aug 14, 2014)

I've done some testing with B+W MRC UV (I have ISO 12233-type charts costing more than some L lenses). I find no impact on sharpness. The only real issue is increased flare in strongly backlit shots.


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## Click (Aug 15, 2014)

neuroanatomist said:


> I've done some testing with B+W MRC UV (I have ISO 12233-type charts costing more than some L lenses). I find no impact on sharpness. The only real issue is increased flare in strongly backlit shots.




Same here.


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## climber (Aug 15, 2014)

neuroanatomist said:


> I've done some testing with B+W MRC UV (I have ISO 12233-type charts costing more than some L lenses). I find no impact on sharpness. The only real issue is increased flare in strongly backlit shots.



OK, thanks. I will try to make a backlit shot with and without filter (have B*W too) and see the difference.


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## aardvark (Aug 15, 2014)

In my experience I am very wary of filters. I have had some serious issues in the past with some makes of UV filters, not sure if the impact is more noticeable on long lenses. 

Interestingly, only last week, I was asked to assess a brand new 400mm zoom lens whose quality appeared "not correct". Frankly it was awful, tried it on number of bodies, etc, etc. Then realised that a UV filter (pretty high end and from reputable source) was placed on end - took it off - wow what a difference. I happened to have a competitors UV and also another brand protector and they didn't have the serious impact on image quality the previous one had

I tend to use high end protectors and always test when I get one (before and after) to check no significant difference. Frankly I was shocked that a reputable manufacturer's filter, fairly high end from a top UK manufacturer (meaning it wouldn't be a fake) was so poor.

So get a good one, form a reputable source, but test it when you get it....


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## Sporgon (Aug 15, 2014)

Agree with those that say a good quality one has no adverse effect apart from flare, but as I shoot into the light a lot I don't use them, unless I'm in a really aggressive environment. The multi coatings of these lenses are really tough.


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## AlanF (Aug 15, 2014)

aardvark said:


> In my experience I am very wary of filters. I have had some serious issues in the past with some makes of UV filters, not sure if the impact is more noticeable on long lenses.
> 
> Interestingly, only last week, I was asked to assess a brand new 400mm zoom lens whose quality appeared "not correct". Frankly it was awful, tried it on number of bodies, etc, etc. Then realised that a UV filter (pretty high end and from reputable source) was placed on end - took it off - wow what a difference. I happened to have a competitors UV and also another brand protector and they didn't have the serious impact on image quality the previous one had
> 
> ...



What was the the bad filter?


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## ecka (Aug 15, 2014)

1. UV filters cause flare.
2. UV filters may cause AF problems.
3. UV filters may cause vignetting on wide angle lenses.
4. Some UV filters may cause slight color tint (haze filters), lower contrast and sharpness.


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## RLPhoto (Aug 15, 2014)

B+w on all my lenses. The difference between is negligible and if your shooting a strong enough back light to get flare off the UV filter, your probably already getting flare from the lens anyway.

However being able to wipe off my lens with a shirt, drop them in and out of bags with no lens cap, grab and touch them anyway I want, avoiding dirt and dust on the front element, and potentially protect against a stray object finding your front element out weigh any nearly invisible difference in IQ. Plus when you resell, the front element looks absolutely perfect.

The times where the filter comes off is when using my LEE system or a polarizer on UW lenses.


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## Invertalon (Aug 20, 2014)

I have tested this a few times with my Hoya HD filters that I use on all my lenses.

I put the camera on a tripod, live-view focused on something with a lot of detail... A brand new crisp $1 bill for example, or distant foliage (leaves, thin branches) or something of the sort.

I would take a picture with the filter off and gently screw on the filter, not adjusted focus or anything. Re-take the shot.

I did this with various subjects and compared at 100% and up in Lightroom... I never saw any detail loss to be honest. It always looked the exact same.

The only thing I did notice, is that the exposure drops an extremely small amount... You can see the histogram shift ever so slightly between filter vs. not... Hardly any issue... But this makes sense, as the filters generally allow something like 99.6% or 99.8% light transmission or something.

So that is my experience... I have tested personally and never saw any difference. If I did, I wouldn't be using them. I never had an issue with flare, either.


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## infared (Aug 20, 2014)

LuCoOc said:


> As usual Roger over at lensrentals.com did it:
> 
> http://www.lensrentals.com/blog/2011/06/good-times-with-bad-filters
> 
> http://www.lensrentals.com/blog/2010/12/the-glass-in-front-of-your-glass-all-about-filters



Yah gotta love Roger!!!! Anyone the would pose for an avatar with a lens sock on his head is my kinda guy.
His test says it all to me! :'(
I use B&W MRC Clear nano filters on all of my L, Zeiss, Sigma glass...all the time. I defy someone to see the difference in the images from any of my lenses with and with out the filter. The filter has saved my $2000 lens more than once out on location. Its just foolish not to. ..but that is just my opinion. I have sold many..many..many images...no one ever asked if I had a filter in front of the lens...or said "Hey, this would be a lot sharper if you hadn't had that filter in front of the lens!" 8) 8) 8)

I also can't buy say an "L" lens and put a $2 filter on it...but hey whateva.


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## infared (Aug 20, 2014)

RLPhoto said:


> B+w on all my lenses. The difference between is negligible and if your shooting a strong enough back light to get flare off the UV filter, your probably already getting flare from the lens anyway.
> 
> However being able to wipe off my lens with a shirt, drop them in and out of bags with no lens cap, grab and touch them anyway I want, avoiding dirt and dust on the front element, and potentially protect against a stray object finding your front element out weigh any nearly invisible difference in IQ. Plus when you resell, the front element looks absolutely perfect.
> 
> The times where the filter comes off is when using my LEE system or a polarizer on UW lenses.



+++1000 ;D


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## mrsfotografie (Aug 20, 2014)

The other day when I was shooting motorsports, a stray stone from the tarmac hit my right hand when a motorcycle was doing a burnout. I was happy my face was protected by my camera, and my lens front element by a UV filter. Nothing hit the front of the lens but it could have been a different story.

I've also changed out a UV filter once because it had scratches on it - from cleaning with a piece of cloth that may have had a spec of sand in it. No harm done to the lens.

So yes, UV filters always except on some vintage (Canon FL) stuff that I own (not worth the extra cost). I have strictly B+W filters on my Canon EF lenses, Hoya and other vrands on the E-mount and FD/FDn stuff.


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## e17paul (Aug 20, 2014)

The only time I have noticed the difference is when photographing through glass using my 50/2.5 macro to take photos obliquely through a London bus window. There's always an extra chance to pick up extra reflections and artifacts with extra glass ahead of the front element. A hood may have helped, but the lens doesn't otherwise need one because the front element is so deeply recessed. Apart from ND and orange filters for b&w film, I haven't used a filter on that lens since.

On my only weather sealed lens, I soon bought a Hoya HD protect (not UV) filter permanently in place. I can't fault the IQ with or without filter.


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## TexPhoto (Aug 21, 2014)

Here is a great test; http://www.lenstip.com/113.1-article-UV_filters_test.html


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## neuroanatomist (Aug 21, 2014)

TexPhoto said:


> Here is a great test; http://www.lenstip.com/113.1-article-UV_filters_test.html


They did some thorough testing, but I'll repost some caveats about interpreting their results in the context of use on a dSLR:



neuroanatomist said:


> Just be aware of how LensTip's scoring is derived. One factor (25% of the scoring) is how effective the filter is at blocking UV light, and that is irrelevant for dSLR users. In fact, in one sense better UV blocking is worse, because some of the deep blue light is also lost.
> 
> Hoya, Zeiss, and B+W all publish their transmission curves. No filter has a perfectly vertical cutoff on a transmission curve - most good commercial multicoated filters that 'block' wavelengths ramp from ~0% transmission to their max of >99% over a 25-125 nm range (although some of the longpass and bandpass filters I use in microscopy are close to vertical, with a slope covering <5 nm - and they come with a price tag commensurate with that performance).
> 
> ...


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## Richard8971 (Aug 21, 2014)

If your a pixel peeper you can tell a difference when using UV filters and I did a quick simple test a little while back to show that under close inspection you can tell the difference between shots when you use one vs. not using one.

http://www.canonrumors.com/forum/index.php?topic=18010.0

But I also proved that under NORMAL viewing of images on the PC, you cannot really tell them apart. Of course a few tried to say that I needed to provide the RAW files so you can pixel peep... etc... but that wasn't the point of it. When you look at an image normally, you cannot really tell them apart.

Even a cheap filer will help protect your glass against minor accidents and scratches. It's cheap insurance and you won't reduce the image quality by any noticeable amount. 

D


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## Hjalmarg1 (Aug 21, 2014)

Sporgon said:


> Agree with those that say a good quality one has no adverse effect apart from flare, but as I shoot into the light a lot I don't use them, unless I'm in a really aggressive environment. The multi coatings of these lenses are really tough.



+1, good quality filters have minimum effect on picture quality. I agree that shooting indoors can save you from using/requiring the extra protection of filters, although I prefer keeping them on, not only for extra protection but also are easier to clean.


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