This month’s column will be divided in two sections because of the sheer amount of information relating to this topic and for this session, I will deal with the various types of filters and holders and why they are helpful to you in photography.
There are two basic types of filters on the market today. The first is the round type that attaches to the front of the lens via threads on the filter itself. Both ends are usually threaded, thus allowing multiple filter use and are generally made from polished multi-coated glass that is a bit higher quality than other substances that are used in the manufacture of the filter described below. The second type is a square piece of glass or polyresin that fits into a square holder that you attach to the front of the lens via an inexpensive metal adaptor. This system is much more economical if you own or plan to purchase other lenses. If you buy the round, screw-on type, then you must purchase one for each individual filter and considering that some filters are well over a hundred dollars, this can prove to be expensive for those who own three, four or more lenses. The square type take only the adaptor for each lens allowing you to use the same filters for every lens that is in your arsenal and making it so much more economical.
The care of these filters is simple and if you treat them as you would a lens, then you’ll have no problems with scratches and dirt or dust. Most filters come with their own plastic case and it is a simple matter to replace them in their cases after use. If you have a lot of them however, they can take much valuable space in your camera bag. I have found that using a CD wallet is the perfect way to carry mine. These wallets are lightweight and come in many sizes, thus allowing me to carry twenty-four in the space it would take to store six with their original cases.
Why should we use them and what purpose do they accomplish? Have you ever shot a roll of what you thought were perfect pictures, only to get them home and see that a lot of the skies were almost white instead of the blue that you saw? Don’t worry, you’re not alone. This has happened to the best of photographers and will happen again, if we don’t do something about our exposure. Now, I’m betting that a lot of you take those less than perfect photos and throw them in a box, never to be seen again. Now hold on just a second. Let’s take a look at that picture and give some thought as to why this has occurred. By learning from our mistakes, we can improve our skill and almost eliminate most of these problems. What happens is: if you expose for the foreground, then the sky is blown out. If you expose for the sky, then the foreground is dark. This happens because the sky is anywhere from two to five stops brighter then the foreground. A neutral density filter takes care of this problem rather well or, you could use a graduated, gray filter with similar results. These filters both hold back light and allow more exposure for the foreground, thus achieving a more proper balance.
Another reason people will buy filters, is to protect the front of the lens from scratches. The theory being that it is much cheaper to replace a twenty-dollar filter then it is to purchase an expensive lens. Usually these filters are a skylight, or UV filter. They both have different uses however and can make a slight change in the colors and clarity of the photograph. The skylight can add a touch of bluish tint to your photo and the UV will cut down distant haze in the shot. Both can prove useful and it is a matter of individual choice, as to which you would prefer. Perhaps you could have both, after all these are relatively inexpensive compared to some of the other types that are on the market.
To the uninitiated, a trip into your local camera shop will bring forth a vast array of filters in various colors as well as for different uses. This can prove to be a daunting experience and can lead to the purchase of unnecessary filters, not to mention wasting your hard-earned cash. By knowing beforehand what you need or hope to accomplish, then it will be a fun-filled experience and one you will look forward to each time.
In my column next month, I will write about some of the filters that can be useful and some that are definitely not.
