Lens filters change the properties of light that enter the camera lens resulting in an array of effects, some more subtle than others, in your photos. For the nature photographer, lens filters are essential to creating better photographs. For the waterfall photographer, a few types of filters are critical for controlling reflections and creating that silky look to water. When I shoot landscapes, more often than not, I attach a polarizing filter to control reflections and deepen colors. When shooting waterfalls, I may also stack on a Neutral Density filter to smooth out the water flow and make it stand out from the surroundings. Even when shooting without the need for an effects filter, I like to keep a clear protective filter on my lens to protect it from dirt, scratches, and acidic water.
Software-based filters have replaced many, but not all physical lens filters.
A lot of classic filters, mostly the colorized filters, can now be replicated using software such as Photoshop. In the days of film, black-and-white portrait photographers would often attach a yellow-tinted filter to their lens to highlight Caucasian skin tones on monochromatic film. This type of filter is not necessary in the digital age, and shooting at the camera’s default color and applying a black-and-white filter in post production is more favorable.
Some lens filters do more than just apply color to the photo, they actually change the amount of light entering the lens. These types of filters cannot be replicated accurately in Photoshop.
SLR and inter-changeable-lens cameras can easily take filters. Most compact cameras will not, without an adapter.
In order to use filters, you must be using a camera that can accept them. SLR cameras (digital or film) as well as other inter-changeable lens cameras (such as Micro 4/3) can accept filters directly on the lens. SLR lenses have threaded ends upon which a circular photographic filter can be attached. Since one may have many lenses of different sizes and shapes for their SLR camera, it may be necessary to purchase several sizes of the same filter to fit each lens.
Many compact or “pro-sumer” cameras, the ones without interchangeable lenses, have the ability to accept attachable filters as well. For many of these cameras, you will most likely have to buy a lens tube filter adapter. This attachment screws on over the lens barrel of your camera and allows you to attach filters to the adapter. Filter tubes generally cost between $15 and $25 and can sometimes be left on the camera as an extra layer of protection for the lens barrel. Your best place to find these at great prices is on eBay.
Less feature-rich compact pocket cameras usually don’t allow for filters to be attached. If your camera cannot accept screw on lens filters, there are kits available consisting of an attachment for your tripod or tripod mount. From the tripod, an extension holds square filters in front of your camera lens. These kits are generally more expensive, but very versatile and interchangeable between different cameras and lenses. A few manufacturers also make a filter holder that will attach to a compact camera with a magnet, allowing for great flexibility and quick removal.
Filters come in a variety of shapes, styles, diameters, and thicknesses.
A Polarizing filter is a must-have for an outdoor photographer. You will get results from a polarizer that you will not be able to replicate in software, even if you are a Photoshop expert.
There are two types of polarizing filters: Circular and Linear. Circular seems to be the most widely available and versatile. It’s the only one I recommend. What a circular polarizer will do for you is:
In a nutshell, a polarizing filter reduces glare just like polarized sunglasses do. It counters the effects of strong sunlight, reducing glare from just about everything; from water to the sky. When you get rid of glare you improve the contrast and saturation of your scene.
Sounds great, doesn’t it? So if a polarizing filter is so great, why aren’t all camera lenses polarized? There are some disadvantages to polarization. Polarizing filters tend to darken the scene, allowing less light to enter the lens, which means the lens performs slower. Shooting with a polarizer means the shutter has to open longer to capture enough light. This can result in blurrier or noisier photos. Polarizing filters are also made of two layers of glass. One stationary layer, and one that is rotated. Two additional layers of glass can reduce the quality of a lens, increasing reflections, distortion and vignetting. A higher-quality, thinner polarizer can reduce those effects, but will add a significant cost to the camera. So, the option is yours. If you don’t mind the trade-offs of a polarizer, you can attach one to your lens as needed.
Using a polarizing filter is fairly easy. It has two rings. Rotating the outer ring will align the crystals of one layer of glass with the other. When the crystals are aligned properly, you will see the glare in the scene greatly reduced. To more clearly see this reduction, point your camera towards a blue sky or a wet surface with reflections. The sky will become a dark blue, and a wet surface will darken and saturate as the reflections disappear. Stop rotating when the effect is at its height.
When using a polarizer filter, it is important to keep in mind that the effect is most prominent when the scene you are photographing is positioned 90° from the sun. The effect will not be noticeable at all when photographing towards the sun or with the sun behind you. If you’re using a wide angle lens, the scene you are photographing may have portions that are 90° from the position of the sun and some that aren’t, which gives a gradient effect of darkening across the sky. Some photographers do not like this effect, but since most skies do not have a consistent brightness anyway, most people will not know this is the effect of a polarizing filter. Find polarizing filters on Amazon
If you like the silky-smooth effect on the falling water of the many waterfall pictures on the site, then you like the effects of the Neutral Density (or gray) filter. Think of the Neutral Density filter as the Ray-Ban sunglasses of the filter world. The job of a Neutral Density (ND) filter is to reduce the amount of light reaching the camera lens without affecting the color of the scene.
If the light entering the lens is cut by 50%, then the shutter has to stay open twice as long in order to properly expose the scene. While the shutter is open for twice as long, the camera is picking up all the water movement that happens during that time and blending it all together in one shot. This leads to the blurring or “silk” (or some call it “cotton candy”) effect on moving water. The darker the scene, the longer the shutter needs to stay open to get a proper exposure, and the more water that rushes past, blurring the scene as the shutter stays open. The longer the water rushes through the scene, the more blending occurs and the result is a stronger blurring effect. To achieve the silk effect, you need to have your shutter open for at least 1/15th of a second. If you kept the shutter open long without a filter, it would just result in an overexposed image (often completely white). Using a Neutral Density filter will help prevent that.
The silk effect is strengthened by the fact that the rest of your scene, the surrounding rocks and the trees, which hopefully aren’t moving while the shutter is open, remain sharp in the resulting photo. It is important to keep in mind that anything that is moving while the shutter is open will end up being blurred. This includes any foliage that may be moving because of wind or any people or animals within the scene. It’s also important, since the shutter will be open for longer than average, to use a sturdy tripod. Photos will be a blurred mess from any handheld shots with a ND filter.
There are three ways to darken a scene to get the silk effect on your water. The first is to shoot after the sun goes down, or before the sun rises, when there is less light. Unfortunately this also changes the colors of the scene and you limit the time available to shoot. The second is to close your aperture (increase the f-stop), which may not be enough for some lenses, and may change the depth of field beyond what you want for your composition. The easy way to reduce light without changing other factors is to use a neutral density filter.
The neutral density filter can be purchased in different strengths; ones that will reduce the light slightly and others that are strong enough to tame direct sunlight. They are specifically designed so as not to alter the color of the scene. When buying a ND filter it’s recommended that you buy various strengths and use them based on the lighting conditions of your scene. If you could just buy one, I recommend starting out with and ND8 for bright scenes or ND4 for those in the shade.
One may also choose to invest in a Half ND filter if they shoot a lot of landscapes. These specialty filters are half gray and half clear glass and are great for shooting scenes in which half the scene is of normal brightness (the ground) and half needs to be tamed by the effects of an ND filter (the sky). These filters come in different strengths, like regular ND filters, but also varying degrees of softness in the transition between the gray half and the clear half. In the digital age I can’t recommend a half ND filter as much as a regular ND filter anymore. If the landscape shot has lighting conditions that are so diverse, I recommend shooting two photographs, one for exposing for the ground or water and the other exposing for the sky. Then you can combine them in Photoshop. Find Half Neutral Density Filters on Amazon
The silk effect of a full ND filter can be imitated in Photoshop, but it is not nearly as good as the real thing. So if you want your waterfall photos to have the silk effect, I can’t recommend a set of Neutral Density filters enough.
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