By Rae A. Costa
Filters are wonderful additions to any photographer's camera bag and there are many kinds on the market to choose from. When used properly, filters enhance your photos by affecting contrast and light intensity. Depending on the type of filter you use, you can also create different special effects or cause highlights. Filters can turn dull photos into eye pleasing memories, but if used wrong they can spoil the entire photo.
As the name implies, colored filters add color to color photos. For example, a picture taken with a red filter will come out with a red tint. Simple, but used with black and white film colored filters can be very effective in changing the light and dark contrasts in a scene. Without a filter, objects of similar color and contrast would look about the same in a black and white photo.
For example, red flowers and green leaves reflect about the same amount of light. If taken with black and white film and no filter, the red flowers and green leaves would appear the same shade of gray with no major distinction between the two. However, if the same picture is taken using a red filter, the flowers will become lighter and therefore stand out more from the leaves.
A green filter will also provide distinction between the flowers and leaves by lightening the leaves and darkening the flowers. The eye is naturally drawn to bright areas in a black and white photo. For your photo you'll want to use a filter that will make the subject light and the surrounding areas darker.
Yellow is another common color used in a filter. Black and white film is more sensitive to ultraviolet and blue light . Objects that reflect a lot of ultraviolet and blue light, such as the sky, appear lighter in a photo. A yellow filter will absorb some of the ultraviolet and blue light thus darkening the sky so white clouds stand out and appear more dramatic.
An orange filter will absorb more of the ultraviolet and blue light thus darkening the sky even more. A red filter, which absorbs cyan and green as well as ultraviolet and blue light, can be used to further darken the sky. Experiment with using various colored filters to learn how they affect the overall look of your photos.
Polarizing filters can also be used with black and white film. Polarizers increase general outdoor color saturation and contrast. With black and white photography, polarizers can darken a blue sky, but the sky must already be blue not white or hazy. These filters also reduce unwanted reflections from surfaces such as water and glass.
Remember, when using a filter it's important to increase exposure otherwise your photos will be too dark. Check the filter's 'filter factor' number and adjust your camera's f-stop accordingly.