Wednesday, April 28, 2010

Filters 102

Today's post is in continuation with our short series of filter posts.  If you missed Filters 101, click HERE. The filters we are referring to are the traditional filters that screw onto the front of a lens, drop-in, or slide in as gels (not the Photoshopped kind).
  • Haze Filters are more intense versions of UV filters. Like UV filters they cut down on the bluish haze accompanying high altitude, far distances, and over-water shots. They contribute a warming effect, and will sometimes create a yellow cast. Haze is created when light hits small particles in the air. Haze filters are able to cut down on the haze created when light reflects off of larger particles in air, such as droplets of water, dust, and pollution. Although the filter cannot remove these particles completely, it can dramatically decrease their effect in photographs.
  • Fog Filters serve the opposite purpose of Haze filters. When it is desired, these filters will increase the effects of fog or subtly create it where none is present. Fog filters can be used to soften a photograph or add more depth to a boring scene by adding another element to it. In scenes where some fog is already present, this filter will exaggerate, or “thicken”, its effect.
  • Close up filters are used to bring the minimum focusing distance of a lens much closer. These filters are a cheap alternative to macro lenses and offer unique qualities of their own. They come in varying intensities (usually from +1 through +10) and can be combined with one another to achieve desired results. Lower intensities are beneficial on flat objects, while more intense close up filters are better for 3 dimensional objects, as they maintain depth of field without sacrificing much sharpness.
  • Soft focus filters diffuse the light coming into the lens, affecting the overall contrast and sharpness, and subtly blending colors. Their effect appears as a soft glow emitting from bright spots, or as an out-of-focus-blending of less intense colors. Although cutting down on sharpness and contrast, they can help objects in a photograph flow together more easily.
Shot with no filter (above)
Shot with soft focus filter (below)
  • Enhancing filters work mostly in the red spectrum. Their use results in a greater saturation of some browns, oranges, and reds. This filter works by not allowing duller colors to pass through. This effect in itself will lead to a warmer photograph, but most filters also add a slight red tone. This makes the colors in the red spectrum jump out and has a warming effect on objects of other colors. Different versions of enhancing filters are made for enhancing specific colors, such as greenhancing, and bluehancing.
  • Cross screen filters are clear filters that have any given pattern of lines running across them. This effect causes light sources and bright reflections to radiate out along these lines. The most popular version of these is a starburst filter. These filters are commonly used at night, creating streaks of light to fill areas that would normally be dark. When used in daylight, the diffusion of light through these filters will sometimes soften the shot depending on the number and intensity of light sources.
  • Split field filters are a type of close up filter that allow the photographer to focus on an object within inches in the foreground, and keep sharp focus on objects in the background. These filters are essentially a close up filter cut in half. The main challenge of a split field filter is hiding the line created by the filters edge, which often shows up as a blur running across the photograph. Despite the challenges that come with using this filter, they can still be useful. Most SLR camera’s automatic settings don’t allow for the photographer to get the maximum depth of field out of their lens. With reliance on automatic features, a split field filter easily offers the desired effect without the frustration of trying to force your camera to do something that it wasn’t set up to do.
An example of the blurry line created by a split filed filter that should be avoided.

~Andy McCarrick