Neutralizing Density: Overpowering the Sun
Content and Images Contributed By Richard Newman
In the not too distant past, lens filters took up about as much space in a photographer’s bag as film. No serious or professional photographer worth his salt would consider going anywhere without a slew of glass or gelatin filters to control such things as contrast and color balance, not to mention creating special effects. Today’s digital cameras have virtually eliminated the need for warming, cooling and color correcting filters, leaving lots of extra space in the camera bag for . . . lunch? About the only filter that remains a constant for most digital photographers is the UV filter, which provides lens protection from the elements.
Well, there is one other type of filter that I still hold near and dear to my heart, and find invaluable in creating unique images that you simply cannot produce without filtration: Neutral Density filters. Let’s start with a discussion of what neutral density filters are and why they are still important for today’s digital image makers.
Neutral density, or ND filters are designed to reduce the amount of light that reaches your camera’s sensor or film without effecting color. They are generally available in three types, each providing a different amount of light reduction. O.3 ND reduces the light by one-half, or one f-stop, 0.6 ND reduces the light by two f-stops, and 0.9 ND reduces the light by three f-stops.
Why in the world would a photographer want to reduce the amount of light hitting the sensor or film? By minimizing the amount of light you are able to shoot at slower shutter speeds and/or at wider apertures in order to create effects that you might not be able to do on a bright sunny day. Photographers shooting film could simply use a slower film, which were commonly available with ISOs such as 25, 32 and 64. But today’s digital cameras, which are constantly racing to increase light sensitivity, seldom, if ever, go below ISO 100. Sometimes there is just too much light in the scene to create your desired effect. Enter the neutral density filter!
A case in point: I enjoy photographing the ocean near my house, and I absolutely love the way the water looks when photographed at ¼-second. To do this on a bright, sunny day is impossible, and even on an overcast day, it’s a challenge. That’s why I always carry a variety of neutral density filters in my bag. Here are a couple of examples:
The top image was shot at 1/2000-second and the bottom one was shot at ¼-second. Quite a significant difference.
The second example shows how a neutral density filter can alter the effects of other moving objects by allowing you to shoot at slower shutter speeds in daylight. The top image was shot at 1/1000-second, while the bottom one was shot at ¼-second.
Neutral density filters can also be very effective in allowing you to shoot at wider apertures on sunny days, which allows you to photograph a portrait or flowers with a more desirable blurred background created by a shallow depth of field.
A Few Things to Note When Considering Neutral Density:
- These filters can be purchased in glass, threaded to fit directly to the front of your lens, or, in polyester sheets that can be placed in a slide-in filter holder. On a practical note, you want to purchase these filters so that they fit your largest diameter lens. In order to use them on smaller lenses, you can purchase step-down rings to fit each of your lenses (see image below).
- Neutral density filters can also be “stacked.” This allows you more creative control under more lighting conditions with fewer filters. In other words, if you only have an 0.3 ND (one f-stop) and an 0.6 ND (two f-stops), you can use them both to reduce your exposure by three f-stops.
Personally, I like to keep over 12 stops of neutral density filters in my bag at all times. They are a wonderful tool towards creating unique imagery and allowing me to “see” my photographs differently in ways that a standard exposure cannot capture.