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Using Filters to Protect Lenses

How many of you use some kind of clear filter to protect the exposed element of your lenses for fear of damaging them? There are a couple of different types that do the job well; UV and Skylight are two that spring immediately to mind and, as their names imply, bring benefits to certain photographic situations.

But there is also an argument against using them, the reason being that adding an additional glass surface to a lens can only detract from the lenses ability to create the best possible image. I am sure this debate will continue for as long as photography exists, but how much of a difference does adding an extra glass surface to a lens actually make?

Now I am not going to be carrying out a scientific analysis of this here, but it is fair to assume that a real world common sense approach is worthy of consideration. So, if you do consider using a protective filter, make sure it is a high quality one. You have probably already spent a large amount of money on a lens, why degrade it by putting a cheap brand filter of dubious quality over the end of it? Look out for manufacturers such as B+W or Hoya who offer high quality multicoated versions. They will be significantly more expensive than many brands but like most things, you get what you pay for. And an expensive filter is going to be cheaper than replacing a damaged front lens element.

I have used UV filters to protect most of my lenses since I began photography, so it is not hard to guess which camp I fall in to. And I learned the hard way that cheap filters are not good, as these were exactly the type I purchased when I started out. Flare was the biggest problem, resulting in dramatic loss of contrast in some situations. Inevitably, buying cheap turned out to be more expensive as I soon replaced them with better performers. The results spoke for themselves; the difference made to my pictures was like night and day. So, one of my golden rules is to always purchase good multicoated filters – no exception. I always allow for this when budgeting for a new lens.

Some of my protective filters are probably getting on for 20 years old now, so I decided to take a closer look at them to see how they have coped being on the front line for so long . I must admit that I am very careful with all of my camera gear so yes, I am protective about my protective filters and use lens caps diligently when gear is not in use. Apart from a small amount of insignificant surface scratches, they seem to have held up fine. The coatings still look intact and the glass is bright. My guess is that they perform pretty much the same today as what they did when purchased.  So, if they bear virtually no signs of use over the decades, why do I need them for protection? Sods law springs to mind here and something I nearly fell victim to a couple of years ago.

I was standing in a ruined crusader castle in the Peloponnese region of Greece at sunset. I had been using a polarising filter to capture images of olive groves and removed it to grab some memories of the sunset. At this point, I was setting up the tripod, with the camera hung around my neck. As I was bending down, the camera slipped and swung downwards towards a limestone rock. I grabbed the camera just before impact with the rock, and noticed that the exposed front element would have taken the full force if the rock and camera had connected. The lens in question was one of my favourites – a Zuiko 50mm f1.2. This lens has been out of production for many years and no spare parts are available. It is also a difficult lens to source on the second hand market, consequently it commands premium process. As it happened no damage was done, but had the lens hit the rock with a filter attached, I would only be looking at replacing the filter. And this scenario demonstrates precisely why I use protective filters – as a form of insurance.