I use very few filters for color photography but the few I use, I use a lot shooting fall colors. I use polarizing, neutral density and graduated neutral density filters. I don't use sunset, warming or "enhancing" filters at all. I prefer the colors natural. I don't like fake color.

Since filters are darker than clear glass they have a filter factor to consider in exposing the photograph. The polarizer absorbs two full stops of light. Neutral Density filters have predetermined densities ranging from one f-stop to five f-stops. If you're manually setting your exposures, you need to remember to compensate for these factors.

Polarizing Filters

Fall colors photography is done at a time of year when the earth is changing its position to the sun and the polarizing filter (photo 1 in slide show) is probably the most useful filter we can use at this time. The polarizer has three functions. It minimizes atmospheric haze, minimizes reflections and deepens a blue sky.

There are a lot of reflections in fall color photography. Every leaf surface and water surface (photos 2 and 3) is reflecting light to the lens. The polarizer can eliminate the glare off these surfaces and produce richer colors. Polarizer's also absorb approximately 2 stops of light. This can be very helpful when a slow shutter is needed to allow action to continue to move during the exposure.

In deepening the sky (photos 4 and 5), a polarizer eliminates the diffracted (scattered) light in the sky behind our trees and allows the leaves to stand out against a rich blue sky. Be careful though because rotating the filter too far makes the sky appear black and can over-do the polarizing effect. Go about half way for a pleasing blue.

Long distance shots across valleys can benefit from using a polarizer because it helps cut through the haze to reveal distinct color in distant hillsides.

Neutral Density Filters

Neutral density (ND) filters are solid grey filters of different densities. They range in density from 1-stop less light to as much as 5-stops less light. These filters are dark and are used to cut the amount of light reaching the film or sensor. By using a neutral density filter, we allow the subject more freedom of motion.

I use ND filters to make long exposures of water6. I will usually combine a polarizing filter (looses 2 stops of light and cuts reflections off the water) and a 3 stop ND for a total 5 stops less light. This, combined with a low ISO setting of 50, usually gets my shutter speed down in the one to ten second range.

Graduated Neutral Density Filters

Graduated Neutral Density (GND) filters perform the same function as ND filters except that they are only coated grey on half the filter. The other half of the filter is clear. Using this type filter allows you to hold back a portion of the photo (usually a bright area) while allowing the darker area (through the clear half) to register on the film. See the samples for situations best suited for using a GND filter (photos 6 and 7).

The best GND filters to use are the rectangular ones that slide in an adapter that mounts on the front of your lens. This allows you the flexibility of positioning the neutral density line anywhere in the frame and even use it diagonally (photos 9 and 10).

All filters should be used carefully so as not to attract attention to their use. Subtle effects are usually the best.

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