UV (Haze) Protective Filters
A question that comes up a lot is whether or not a UV/Haze protective filter should be purchased for every lens you own. In fact, the use of a UV/Haze protective filter has become so common that for many people, it is just what you are supposed to do. But does it really make sense? This article explores the pros and cons of investing in a UV protective filter.
Like many people, when I bought my first digital SLR camera, the salesperson suggested that I also buy a UV filter with the camera and kit lens combo. I knew my friend used filters and figured I probably should too, so I went ahead with it without much thought. Now, a number of years later, I am questioning whether buying one of these filters for each lens purchase and leaving it on all the time is the best idea.
But why is this such common practice in the first place? It started in the film days because 35mm film is much more susceptable to UV rays causing a decrease in contrast in outdoor photos and using a UV filter would help minimize the negative effects of the UV rays. Digital sensors are not nearly as susceptable to UV image degradation as film is, so from a UV perspective, the filter does not help with image quality. With no image enhancement benefits, a UV filter really just protects the lens glass.
Knowing that a UV filter will not enhance the image, will a UV filter hurt image quality? You could argue that any time you add a layer between you and your subject you are introducing the potential for degrading your photo. Below are some considerations to think about.
Using a UV filter will make your pictures more prone to flare and/or decreased contrast on a bright day. Companies offer filters with a Multi Reflective Coating (MRC) that can help minimize lens flare and contrast loss. The filters I have with the Multi Reflective Coating also seem to be easier to clean and have noticeably less friction when you are cleaning them.
UV filters range in price from really cheap to hundreds of dollars. If you are going to use a filter, I certainly wouldn't get something in the really cheap category. If you don't mind the potential for flare, there are some reasonably priced UV filters without the MRC from reputable companies. Of course, Multi Reflective Coated (MRC) UV filters are on the higher end of the range.
When considering UV filters for protection, you really need to consider the value of the lens you are trying to protect. A very common lens people get is a 50mm f/1.8, which run for around $100. The cheapest B+W UV filter that fits it is about $20. So you are paying around 20% of the cost of the lens for an "ok" filter. If you are concerned about flare and want one with a Multi Reflective Coating, you are looking at just under $40 for a B+W. That is 40% of the cost of the lens! You can make the same argument when talking about using UV filters on a kit lens. And if you are buying filters for both lenses, you might as well save the money because in most cases the chance of wrecking the front element is slim, and the money you save could go a long way towards a replacement if something were to occur.
Most third party lenses come with lens hoods. As do most professional grade first party lenses. But if I'm looking at buying a 50mm f/1.8, or any other lens, I'm going to make sure I have a lens hood before I am even thinking about a filter. It is going to offer me a lot of the protection a filter would, but also help me get better pictures. If you are curious how much a lens hood would help, go out on a sunny day and do a simple test by putting your hand on your forehead (like you are saluting) to block out the sun and then remove it. There is a noticeable difference, and you will see that in your photos as well in the form of increased contrast and reduced lens flare.
Vignetting can also be a problem with filters, especially on wide angle lenses and/or full frame sensor cameras. This is even more of an issue when you couple a polarizing filter on top of the UV filter.
All of the negatives aside, protective filters can have their place, and I do use them in certain situations.
Some professional series lenses are weather sealed, but require the use of a filter to complete the weather sealing.
If you are going to be shooting in harsh conditions such as near the ocean where salt spray and blowing sand could wreck havoc on your front element. For my honeymoon in Hawaii, I bought UV filters for all of the lenses I was bringing.
Some of my lenses have the lens element very close to the end of the lens and/or the lens hood isn't very deep, so depending on the cost of the lens, it may make sense to protect those front elements that are more vulnerable. I use a UV filter on my wide angle lenses (17-40mm f/4L and Tokina 11-16mm f/2.8) and my "L" walk around lenses (24-70mm f/2.8L and 24-105m f/4L) because the glass is so close to the end. I typically don't use one on my 70-200 f/2.8L IS or 50mm f/1.2L because I shoot almost exclusively with a lens hood and the element on the 50mm is recessed a decent amount.
Using a UV filter can be a good selling point when you go to sell the lens since buyers seem to be more comfortable with the idea that the front element hasn't been exposed to anything that could be potentially damaging.