Lawrence Ripsher

UV, NC (Neutral Colour) and other clear piece of glass – what you put in front of your expensive lens for protection. I gave these very little thought when I first starting buying lenses. I’d always wanted to protect the front element from scratches, damage, etc – so went for the nearest filter, about $20 or so.

Then one day I noticed that the lens wasn’t letting in as much light as I felt it should. A simple test confirmed this – I unscrewed the filter and moved it in front of / away from the lens multiple times and I saw the shutter speed increase.

OK so I needed a better filter and decided that’s what I’d get as I was starting to buy progressively more expensive lenses. "Completely clear" became inelegant the way I’d describe what I was after to the people in camera stores when looking for to get a new filter. It wasn’t until I started researching this area that I realised how much difference exists in the choices.

It turns out if you’re going to insist on putting a protective filter on the front of your lens, anything less than a top of the line "super" multi-coated UV filter will dramatically effect the image quality. One of the major culprits is contrast – with a low quality filter, the blacks do not appear as black and can result in a significant degradation of the final image. Another issue is flare which can bleed into an image and ruin parts of it if the filter is of a poor quality.

So, on a decent lens, a high quality filter such as the Hoya Super HMC Pro 1 is what I would recommend. Hoya claims this filter lets through 99%+ of the original light, and therefore the loss of contrast is significantly reduced. This is the filter I use and definitely recommend it. Other filters I’ve heard people swear by are the B+W series. The cost of these filters is actually not that much greater than the lower quality ones. I paid about USD $60 for my 77mm sized Hoya. And that’s the irony perhaps – that we spend thousands of dollars on lenses and by saving a few dollars on the final piece protective glass that goes in front, we undo a lot of the benefit of that lens in the first place.

I don’t have test / difference shots but can do some if anyone’s interested. However, it’s a topic that’s been covered before and an excellent review summarising this issue can be found here. The guy here does  a great job of showing exactly how big a problem this can be.

So the ultimate question is – "to UV filter not to UV filter"? For me, it’s a fairly easy decision. I shoot in environments where the lens can often get dirty, can potentially get struck by a foreign object and so on. In these situations, I’ll always have the filter on as with the high quality filters, I consider a little degradation in image quality to be an acceptable trade off compared to scratches, etc. Protection of the lens is more important to me in those cases. However, if in a studio, more controlled environment or somewhere which has stage lights /very significant contrast lighting, etc, then it will come off temporarily for the shoot. The decision and trade off you’re willing to accept is ultimately up to you but if you are gonna filter up, I recommend you get the best you can find.
For the little extra cost, it’s definitely worth it.