DSLR owners, both new and old, take note: it's not all about the lenses. An extra piece of glass can be a great way to expand your camera's abilities — but it's also an expensive investment you don't necessarily need to make. There's a much cheaper way to get more from your old lens, and all it takes is a filter.
Filters — to use a tired, but apt cliche — come in all shapes and sizes. In fact, there are a myriad of great filters that can both alter and even improve the look of your pictures. And you don't have to break the bank either. Here's how.
Sizing
Filters come in two varieties: screw-in, and plate. The former fits onto the front of your lens, while the latter is a piece of rectangular plate glass attached with a lens-mounted adapter. It's important to note that screw-in filters are not interchangeable — that is, they won't always work from lens to lens. Different lenses have different size threads — 52mm, 67mm, etc. — with larger filters costing the most. Though you can buy special step-down rings that convert between threads, be sure to take these variances into account.
Polarizers
Reflections are a nuisance, but they're easy to deal with. A circular polarizing filter, when used correctly, can cut through sources of reflection and glare, while improving the saturation and contrast of many outdoor scenes.
This is especially evident when taking pictures of glass, windows, or water. On a coastline or beach, for example, a polarizing filter will not only eliminate the shimmer of the water's surface, but darken the blue of both sea and sky for a more dramatic effect. For best results, says photographer Michael Reichmann, "polarization is most effective at 90 degrees to the sun" — achieved by rotating the two-piece element on most screw-in filters.
Of course, there are caveats. Using a polarizer is like wearing a pair of sunglasses, so expect your aperture to effectively increase by one to two stops or more. Also, because a polarizing filter relies on the availability of light, changes to contrast or saturation will be largely absent on cloudy days. Still, it's the cheapest way to give that old kit lens some additional "oomph."
Neutral Density
If you live in a place lucky enough to get snow, you know that sunny days can be particularly harsh. The white snow acts as a giant reflector — bad enough to look at with the naked eye, but even worse for taking photos. Everything appears especially bright.
In situations like this, neutral density (ND) filters can be used to great effect. Similar to a polarizer, ND filters come in a variety of strengths, and work to darken the overall image in varying degrees. In outdoor environments, this is incredibly useful. A wider aperture can be used for a more shallow depth of field, while keeping your shutter speed the same. Alternatively, the darker glass means that longer exposures can be used, handy for capturing daytime motion blur.
Graduated ND filters also exist, and as you might guess, only darken part of the image. As you can see in the image above, this can create the impression of a darker, more dramatic sky, while leaving the water untouched.
Ultraviolet
The argument for and against UV filters is about as old as the practice of digital photography itself. Some swear by their ability to protect expensive lenses from scratches and scrapes, while others decry the reduction in image quality that supposedly results from their use. Hard evidence is hard to come by either way, and amusingly, modern cameras do a fine job blocking UV interference all by themselves. We leave the choice up to you.
Infrared
Traditional photography requires special infrared film and filters to capture the Infrared spectrum in a manner we can perceive. Digital cameras, however, are a different story. Because Infrared light can interfere with a sensor's ability to capture "natural" looking images, most manufacturers employ some sort filter to block IR light out. This is good for most — except those who actually want to let that Infrared light through. It's possible to remove this filter, but at the cost of shooting normal images ever again.
What makes an Infrared image so great? Objects appear very different under the Infrared spectrum than that of visible light — almost otherworldly. Bright skies appear dark, while darker objects appear almost white. Needless to say, the effect is unique, and also particularly useful for cutting through haze, glare and similar nuisances.
However, you don't necessarily need to shoot film or modify your camera to shoot infrared images. In fact, with a special Infrared filter, it's likely possible to use your current DSLR — though we can't guarantee the process will be easily. In order to compensate for your camera's IR-blocking filters, longer than usual exposures are required, some as long as 30 seconds. This will obviously require a tripod, a relatively non-moving subject, and a lot of trial and error.
Warming and/or Cooling
Before the niceties of digital SLRs, white balance and color temperature was not something you could automatically adjust — it was an art, and one that took careful consideration to get right. Though warming and cooling filters have been largely displaced by post-processing effects, some photographers still make use of graduated models for more faithful results.
If you do choose to dabble with these orange or blue tinted filters, just be sure to turn off your digital SLR’s auto white balance functionality, as it will try to compensate for that extra piece of colored glass you’ve placed on top.
Have any lenses you can't live without? Suggestions we haven't yet covered? Let us know below!
Lead image via Flickr user P^2 - Paul.