Our chief photographer shares his insights.
By Earl Nottingham
The right filter helps light and dark elements play well together.
It was the time of day photographers look forward to, when late evening sunlight becomes warm in color and the landscape is sculpted by long, skimming shadows, revealing shapes and textures not seen in the earlier light.
The composition in my viewfinder was a serene stretch of the Rio Grande River snaking lazily through volcanic hills and tamarisk-lined banks; the water's movement on this calm, hot afternoon evidenced only by dancing highlights on shallow riffles. The verdant foliage was beginning to come alive with vivid color, illuminated from behind by a low evening sun. In the top of the frame, lazy cumulus clouds floated in the bright southwestern sky, adding a creative element to an otherwise monochromatic blue and boring, sky. Artistically, I knew the scene was fine. Technically, I suspected there might be a problem getting the film to interpret the scene as my eye saw it.
Light meter readings from both the sky and ground portions of the scene confirmed my suspicions. There was more than three f-stops difference between the bright sky and the darker land area. This meant that if I exposed the image to render detail in the trees and river portion, the sky would go almost white. If the exposure was brought down to favor detail in the clouds, the ground would go almost black. It was time to bring out one of the best-kept secrets in the landscape photographer's camera bag — the graduated neutral density filter.
The graduated neutral density filter is nothing more than a clear glass or plastic filter, usually square or rectangular in shape, which makes a gradual transition in increasing densities of transparent gray, beginning about halfway up the filter. Major suppliers of graduated filters include Tiffen, Cokin and Singh-Ray. These filters are generally designated based on density points of light reduction, 30 points of density equaling one f-stop. An ND.30 filter will darken the image by one f-stop while an ND.60 equals two f-stops, usually up to ND1.20. Manufacturers also make graduated filters in various colors for special effects. I typically carry an ND .30 for slight darkening and an ND.60 for stronger correction of bright skies, just like the one that was before me.
As I slid the filter into the holder on the lens there was initially no difference as seen through the viewfinder. However, as I moved the filter lower, the glaring white clouds began to lower in intensity, revealing an almost painterly quality. The sky and the ground were now within two f-stops of each other, ensuring that adequate detail would be recorded in both the brightest and darkest portions of the image. Slight up-and-down corrections with the filter finally hit on the image I had envisioned. One last check for focus and exposure and the shutter was fired — luckily not a moment too soon as the sun immediately slipped behind a large cloud bank, taking its magic light with it.
For more information, contact Cokin Filter System at <www.cokin.com>, Tiffen Filters at <www.tiffen.com> and Singh-Ray at <www.singh-ray.com>.