# Better UV Protector Filter Increases Image Quality: Example



## sabbath999 (Nov 14, 2007)

When I first bought my 70-200 f/2.8 VR I got a Hoya HMC UV Protector filter, figuring it would do just fine... but I wasn't pleased by the level of sharpness with the lens... 

So the next order I placed I purchased a B&W UV filter, and you can REALLY tell the difference, big time on the two.

I did a little test (shooting a decoration on a neighbor's porch), the first shot is an enlargement of a sign blown up to 400 percent with the Hoya filter taken when I got the lens, and the second is with the B&W taken today (the sun was a little different, hence the slightly different brightness levels).

The distance and subject were identical.

The third shot shows what I blew up the sign from (70mm f/2.8 no VR)

















This last is the same display shot at today 200mm wide open at f/2.8 1/800 ISO 160... I can finally say I am pleased with the sharpness of this lens (it wasn't the lens at all, it was the dad-gum filter on it that was causing that slight bit of image deterioration).


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## YoungRebel (Nov 14, 2007)

Good Thread! Now, finally I see the quality-difference between the filters....

(btw: look *HERE* if you're interested in a brand-new B+W filter)


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## Josh66 (Nov 14, 2007)

Is there any noticeable difference between using the B+W filter and using no filter at all?
(Does the protection added by the filter (I assume that's why you're using the filter) come at the cost of reduced image quality?)


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## YoungRebel (Nov 14, 2007)

that's why I decided to use one after researching:
1.) It is a great way to protect you're expensive lens
2.) Good quality filters (uv) are supposed to filter UV-rays and can
make pictures clearer if the air is a little ?foggy? (dont know if that is the right word for it)


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## FidelCastrovich (Nov 14, 2007)

I thought the general agreement was that UV filters on digital were useless, due to the properties of the light-sensitive surface, which is quite different from film.

Also, regarding the test - you should conduct it back to back, at the same time of day, same exact conditions, using a tripod and remote release or timer. Otherwise, the difference could be due to camera shake, difference in air clarity, etc'.


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## Garbz (Nov 14, 2007)

Nope digital cameras have Low pass filters on their sensors. UV is of higher frequency than visible light. It's the lower frequency infra-red light which is being blocked on the digital sensor. Mind you this does not mean it is the same for all cameras.

Yes I too would be interested in a re-shoot the top picture looks like the blur is vertical only. That could just be a filter characteristic, but a reshoot would definitely rule out camera shake.

Anyway score another one for team take of your filter when shooting something important.


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## TCimages (Nov 14, 2007)

interesting. This is the biggest reason I personally have never used a filter on a lens, especially the ones you spend $1K plus on. I've always just used the hood and caution. Accidents do happen though.


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## sabbath999 (Nov 14, 2007)

FidelCastrovich said:


> I thought the general agreement was that UV filters on digital were useless, due to the properties of the light-sensitive surface, which is quite different from film.
> 
> Also, regarding the test - you should conduct it back to back, at the same time of day, same exact conditions, using a tripod and remote release or timer. Otherwise, the difference could be due to camera shake, difference in air clarity, etc'.



You are correct, if I was doing an actual scientific test my methodology is very poor... however, I was just giving an example. It is obvious on every single picture that I take, so I just went back and reshot one that I had in my folder as a quick example.

I could shoot a boring wall on a tripod if anybody really wants to see that, but the only reason that it would be of any use is that the framing would be exact instead of "darned close" ... but since I was shooting at like 800th 
of a second, fast enough to stop the spokes of a professional bicycle rider in motion there is zero chance of camera shake at those speeds.

Partially cloudy days from 75 feet away are not going to have much difference in air quality either. The only difference between the two days is that the sun ducked behind a cloud yesterday... I have a few shots a bit later where it was out and at the same angle

However, if it is important to anybody I can do this.

I can tell y'all however that the difference is quite obvious on the overall quality of the pictures coming out of the lens, especially where I have reshot the exact same thing (the C-Store across from my office is another usual suspect for my informal tests... I prolly have 300 pictures of that station on my computer).


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## sabbath999 (Nov 14, 2007)

Garbz said:


> That could just be a filter characteristic, but a reshoot would definitely rule out camera shake.



I can reshoot it sometime if you really want, but I just looked at the exif on the original and it was ISO 160, f/2.8, 1/2500th of a second. Pretty sure it wasn't camera shake.


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## Alex_B (Nov 14, 2007)

This is interesting, since for my good glass I use exclusively B+W 
filters, I could never really check the difference ...


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## sabbath999 (Nov 14, 2007)

Now, as far as the filters on the lens thing goes, let me tell y'all a story of what happened the first zoo I took the 70-200 to.

I was shooting the lens at the St. Louis Zoo, with the HUGE lens hood on it, and was taking a picture of a zebra. Another zebra got startled by something, turned around and kicked towards me in a big puddle of water and SPLAT! right in the middle of the lens, as perfectly centered as you could imagine, was a big glob of mud. The rest of me was somewhat peppered as well.

I don't know about y'all, but I would have been more than a little sick to have this disgusting blob of zebra mud splattered all over my brand spanking new $1649 USD lens the first time I used it.

I cleaned the filter by carefully removing most of the mud (which was soft clay) and then running it under water so as not to scratch the filter. It came up no apparent worse for wear (and yes, my first "test" shots were taken BEFORE this, on the day I got the lens).

Image quality be damned, there is absolutely, positively NO way I would ever take a $1650 lens that I had to pay for into the field without a filter on it.

I come from a sports photography background, and have been sprayed countless time by mud, rain, sleet, snow, blood and sweat... lens protection is VERY important in my world.


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## Garbz (Nov 14, 2007)

sabbath999 said:


> I can reshoot it sometime if you really want, but I just looked at the exif on the original and it was ISO 160, f/2.8, 1/2500th of a second. Pretty sure it wasn't camera shake.



Ahhh then don't bother. The exif on the two crops are missing and I didn't know which image the resized one belonged to. It did say 1/800th but you mentioned they were shot at different times so I didn't know. All good then !


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## JerryPH (Nov 15, 2007)

Well live and learn!

Seems I will be going out and repurchasing a few UV filters when I place my order for a couple of polarizing filters.  At the same time that I puchase any lens, I get a UV filter to protect it.

I understood that the UV filters were supposed to be optically "transparent" to the lens and had no effect.  I just learned differently, unfortunately it will cost me a littl $ to rectify.

Before I do any purchases, I plan to test each lens with and without the UV filter and if I find a difference, that filter will be replaced.

Thanks for the heads up!


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## Desire (Nov 24, 2010)

What is the difference between the HMC filter you mention here with the Hoya Pro1D one? I am curious, I bought this one and wonder if I have to worry about this too on my 70-200 4.0


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## Jcampbelll (Nov 24, 2010)




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## den9 (Nov 25, 2010)

this thread is also 3 years old


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## KmH (Nov 25, 2010)

:gah:


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## Garbz (Nov 25, 2010)

:cheers: calm down KmH


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