UV "Clear" filter degrades image

B

BrianF

Member
After reading some threads about the effects of a clear protective lens filter on the image, I decided to do some tests today. I shot the same frame with and without a (clean, nearly brand new) Tiffen 82mm "Clear" filter on the lens.

The results confirmed my suspicions: There is a significant difference with and without the filter. The difference is most pronounced in the screen grabs below, where I purposefully found some lens flare to exaggerate the effect, but other shots, with the camera in the shade, also showed a less dramatic but still detectable difference. Darker parts of the frame showed the greatest changes. At longer lens settings, the effect all but disappeared.

I'll be stepping up to a Schneider filter now to see if that helps...
 

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More screenshots

More screenshots

A couple more shots, without exaggerated lens flare.
 

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It's a regular filter. It reads "Tiffen 82mm Clear USA" on the side. It was also relatively cheap--something I bought with the camera just to protect the lens for the time being.

When I get the Schneider I'll A/B test them against each other similarly.
 
I have a B+W 82mm (MC) UVA Haze filter (Barry seems to use the same) and never experienced this kind of problem. But to be honest I never made a serious comparison no filter/UVA filter.
 
You should only ever use the very best filter made.

It makes no sense to me whatsoever for someone to buy a $6,000 high-def camera, and then put a $10 piece of coke-bottle glass on front of it "for protection." You will be degrading each and every frame of footage you shoot.

I have the B&W MRC filter as mentioned, but I don't just leave it on at all times. I use it when there's a chance that the lens will need some protection. If I'm shooting in a dusty/hazy/smoky environment, or using the camera strapped to a car or something like that, then yes the filter's on. If I"m shooting an interview, no the filter is off.
 
Thanks for the advice, Barry. For some reason I have subscribed to the orthodoxy that says it's foolish not to keep a UV on all the time to protect the lens. Virtually everyone says that.

Yet, in several years of using photo and video cameras I have never once had to replace a protective filter because of damage -- which would seem to suggest that I never would have had to replace a lens had I not been using a protective filter.

Your strategy makes the most sense to me -- use the best filter, but only when damage risk is high. Otherwise, I'm potentially degrading all of my images to protect against a slight risk of damage. I think I'd rather accept that small risk as a calculated cost of doing business, and get higher quality images in return.

Anyone know what the lens-replacement cost is for the HVX? That number minus the cost of the filter would seem to equal the damage risk of going unprotected.
 
Barry, did you test what the impast is of your B&W MRC filter? It would be nice to see the effect with and without filter like Brian did. So if you have the time and opportunity to do this test it is appreciated very much
 
Barry_Green said:
I'd have to wait for some actual sunshine -- it's dark and gray and overcast over here right now.
Click to expand...
Hahaha, that was never a problem in Vegas...perhaps a little TOO MUCH sunshine there...:Drogar-BigGrin(DBG)
 
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