Camera lens filters give you added control over the imagery you produce. Sometimes they are used to make subtle changes to the images; at other times, the images would not be possible without them. Lens filters can be used to help minimize glare and reflections, enhance colors and reduce the light coming into the lens. They may be a square or an oblong shape, mounted in a holder or slipped into the lens. More commonly, the filter is a glass or plastic disk with a ring you screw directly onto a lens. When using a filter, you will need to adjust your exposure because the filter reduces the amount of light transmitted. Once you mount the filter, use the exposure setting indicated by your light meter.
Special effects filters can be used on the camera, or the effects can be created with photo editing software, such as Adobe Photoshop. The ethics policy in the DoDI 5040.02 prohibits the use of any special effects filters that change the content of the photo with color cast, fog, smoke or multiple images.
Each lens filter serves a specific purpose. Explore how using each filter can help enhance the final look of an image.
An ultraviolet filter is mostly transparent for visible light and can be left on the lens for nearly all shots. There is usually no visible difference in the image it produces with or without the filter.
- Reduce haziness
- Reduce blue tones from shadow areas
- Filter out bluish cast created by ultraviolet light
- Protect camera lens against moisture, dirt and scratches
A neutral density filter is basically the equivalent of sunglasses for your camera. The filters create a reduction in all wavelengths of light and do not affect color balance.
- Allow longer exposure times or larger apertures, where these settings would typically create overexposure in the camera
A polarizing filter adds depth to an image by saturating color and reducing reflections.
- Darken overly light skies
- Reduce atmospheric haze and reflected sunlight
- Reduce reflections from smooth, shiny, non-metallic surf