Autumn is prime time to make images of vibrant foliage offset against crisp autumn blue skies. It's the most colorful season so it stands to reason that more images of trees are made in the fall than any other time of the year. The western US offers palettes of yellow aspens with occasional hues of orange and red. The east is more well known for its plethora of color from its hardwood maples, oaks and birches. Mix in a solitary evergreen as a counter point and the results can be dramatic. To maximize drama in fall landscapes, I carry three filters all the time. I encourage you to do the same to increase your chances of coming home with winners.
Number 1 on my list of autumn filters I'd never leave home without is the POLARIZER.
Sky Benefit - A polarizer deepens and saturates a blue sky. On a color wheel, yellow and blue are on opposite sides. The lighter yellow leaves come forward while the blue of the sky recedes. In that yellow abounds in the fall, the leaves become prominent. Maximum polarization occurs 90 degrees to the sun. If you try to polarize a front lit subject, you won't see the filter's effect. A polarizer also cuts through haze which otherwise reduces contrast in the image.
Color - Dependent upon the angle of the sun falling on the subject, glare can negatively impact the image. A polarizer helps cut through glare to restore the true color of the leaves. The result is a more saturated looking scene.
Water - Reflections from the sky often form on a body of water. If the fall color is around a lake and the sky reflection causes a distraction, spin the polarizer. Depending on your angle to the reflection, the distraction can be totally removed. If you don't see a change, walk around the lake and spin the polarizer at different points along the walk. You'll learn the polarizer's nuances regarding how the angle of the light determines whether or not the reflection can be eliminated.
Graduated Neutral Density: A graduated ND filter has a dark top and a clear bottom. I recommend their use to tame contrast when shooting reflections and also to tame contrast at sunrise and sunset. Place the dark part of the filter over the light part of the image area. The result is a more evenly lit photograph. Depending on the situation, it may call for a one, two, or three stop difference. Thankfully, these filters are made in each of these strengths. Additionally, there are soft and hard edge options. If the transition point between the light and dark area is abrupt, use the hard edge variety. Conversely, if there's a smooth gradation, the soft edge is more beneficial. Ultimately, the end result should look improved and natural. A pet peeve of mine is when I see a graduated filter improperly used on a reflection. If the end result is a reflection that comes out lighter than the section of the image being reflected, the photographer used a filter that was too dark which results in something that just isn't natural.
It's important to use the DOF preview button to accurately position the dark part of the filter over the light area of the image. If you fail to do this, unless you shoot the scene at a wide open aperture, the aperture at which you're shooting impacts the transition point of dark to light. With the lens stopped down, the line of delineation in the photograph will not be in the same spot when viewed with a wide open aperture.
Neutral Density Filter: Autumn drives nature photographers to waterfalls. Maybe it's the fall color that grows around them, maybe it's the swirl of leaves that whirlpool in the waters, or maybe it's that waterfalls simply exist in forested areas. Regardless of their lure, a commonly used technique is to give the water a cotton candy effect. This is achieved with slow shutter speeds. In order to obtain the effect, shutter speeds in the one second range are used. If after lowering the ISO to your lowest number and stopping the lens down to its smallest aperture you still can't get a one second or slower shutter, attach a neutral density filter. I carry a three and six stop to make sure I can get as slow a shutter as I want. The principal behind them is they cut back the amount of light and impart no color shift to the scene - hence their name: neutral, no color shift / density, cut back the amount of light. My six stop filter really darkens the viewfinder. I first make my composition and then screw the filter onto the lens. Used interchangeably with the three stop ND, I have the luxury to try different shutter speeds. I think of it as bracketing the effect of the shutter speed.
Visit www.russburdenphotography.com for information about his nature photography tours.