Lens Filters
Why do you need a lens filter in the first place? This is a common question from many photographers who think that the in-built tools in some cameras or some post-processing software like Photoshop makes the filters unnecessary. However research and experiments have shown that its almost impossible to simulate some filters using software such as Photoshop. Some filters actually lay a foundation for better image quality during post-processing.
Lens filters are widely used in photography and can serve different purposes. While some photographers rarely use lens filters in their work, others is a must-have companion in their day-to-day work. If you ask majority of camera owners why they keep a filter on their lens, the most likely answer would be protection. Though the lens filter shields the surface of your lens against dust, moisture and even thumbprints, they also have other prominent position in photography.
Depending on the type of filter and technique of use, lens filters can be extremely helpful in capturing scenery in difficult lighting conditions as well as enriching colors and reducing reflections. A lens filter gives the photographer more control over how much light strikes the camera’s image sensor. For example, some filters blocks light waves so that the shutter remains open longer to smooth motion (say you are taking a shot of a waterfall). Others blocks specific wavelengths to control that light the camera records. Ultimately, they are really useful in improving the image quality.
Perhaps, the best comparison to the lens filters is the sunglasses we wear. The apparent reasons why we don sunglasses is to protect our eyes from dust brown by strong winds and the extreme light, not to mention shielding our eyes from the harmful ultraviolet (UV) rays. The filters are the ‘lens’ sunglasses’ and serve the similar purposes for the lens.
With the many different kinds of lens filters in the market, how do you settle on the one that best suit your needs? Just as some sunglasses would not be appropriate for some eyes in some circumstances, improper use of lens filters can actually destroy your photos. It is therefore critical not only to know which filters to use, but it is equally important to know how to use them and the best situations to use them.
Types of Lens Filters
In terms of physical characteristics, there are inexpensive filters that are designed to be mounted directly onto the end of a lens of the same diameter i.e. a 52mm filter is mounted on a 52mm lens. However a converter ring can be used to mount a filter to a lens of a different diameter. Alternatively you can use one filter to work with different lens using adapters, introducing flexibility and versatility. In this case, the filter is just a glass sheets that fit into lens adapters with mounts.
Converter rings can step up or step down like the K&F Concept 18pcs Camera Lens Filter Metal Stepping Rings kit below that has 9pcs step up rings and 9pcs step down ring set.
An example of lens adapter is the Fotodiox Pro Lens Mount Adapter below. It enables the Canon FD & FL 35mm SLR lens to Canon EOS (EF, EF-S) Mount SLR Camera Body, with Built-In Aperture Control Dial.
When buying filter kits, it is critical to verify your camera’s lens thread size before ordering for compatibility. The camera’s lens thread size will be marked somewhere on the lens barrel or printed underneath your lens cap. This number is always preceded by a “ø” (diameter) symbol.
There are three major types of lens filters namely;
UV/Clear/Haze Filter: You may want to generally refer to UV filters as the ‘bodyguard’ of the more expensive lens. This filter blocks the ultraviolet light waves from affecting the clarity. Most, if not all, digital cameras are fitted with UV/IR filter and thus its not necessary to use a UV filter on DSLRs. However the older cameras require the filters to protect the film from the destructive UV rays. UV filters are inexpensive and therefore easier to replace, they also protect the lens from potential scratches, dirt and moisture.
The Canon 67mm UV Haze Filter above is rather a cheap universal filter that fits into most lenses with 67mm thread diameter. While is protects the lens from bumps, scratches and dust, it also reduces excessive blue (the strong harmful light) and also absorbs UV light and minimizes haze in outdoor photos Amazon also sells a similar 67mm filter, the AmazonBasics UV Protection Lens Filter, that perform the same functions as the one above.
Polarizing Filter: In photography, polarization is a property of transverse waves that specifies the geometrical orientation of the oscillations. Some people want to refer to these filters as the ‘wow factor filters’ due to the effects they have on shots. The filter alters the way the camera sees and treats light, in particular how a camera sees reflections and glare. The polarized light is filtered out, dramatically reducing reflections, enhancing colors and increasing contrast. As a result it has the ability to change the vibrancy of some colors in shots. Polarizing filters can also reduce haze, which is very useful for landscape photographers.
There are two types of polarizing filters – linear and circular. A linear polarizer in photography is a device that allows the passage of only certain orientations of plane-polarized light, say only vertically polarized light. Linear polarizers should not be used on DSLR cameras, because they can result in metering errors. Circular polarizer is just a linear polarizer combined with a quarter wave plate, which converts the linear polarized light that comes out of the first part of the filter to circular polarized light. The conversion to circular polarized light makes the light behave the same as unpolarized in the camera thereby preventing the strong risk of interfering with the DSLR cameras AF and metering functions. Circular polarizers are therefore perfect for DSLRs due to this aspect of their construction.
The 52MM Circular Polarizer (CPL) Filter for Nikon above is a cheap circular proprietary filter for Nikon lenses. Key among its uses is eliminating reflections, color saturation, darkening the sky and simulating dramatic clouds. Amazon also sells own cheap 52mm universal circular filter, the AmazonBasics Circular Polarizer Lens. A more expensive variety from Nikon is the Nikon 77mm Wide Circular Polarizer II Filterbelow, which is a thin style filter for use with wide angle lenses and is multi-coated for higher quality images.
Neutral Density (ND) Filter: ND filter is neutral gray in color so that the amount of light entering the lens is reduced, but the color of the light isn’t changed. The darker the gray color, the more the light is reduced. The photographer is therefore able to control the exposure, enabling the reduction of the amount of light reaching the image sensor of the camera over the entire scene of your image. As a result, you can adjust the shutter speed and aperture settings that are required for proper exposure of an image, allowing you an opportunity to use these settings more creatively. You can chose to use large aperture opening to create a shallow depth of field or a slow shutter speed to create the blur of motion, even when the actual scene lighting won’t allow for these exposure settings.
A 58MM Neutral Density Professional Photography Filter Set (ND2 ND4 ND8) from Altura Photo above, is a popular ND filter for Canon lenses. It reduces the amount of light that passes through the lens by 1, 2, 3-Stops and also allows for reduced shutter speeds, and wider apertures in bright light. Another popular ND filter is the K&F Concept 58mm ND Fader Variable Neutral Density Adjustable ND Filter below, again mostly compatible with Canon lenses.
