ND Filters
Shooting your DSLR camera with Neutral Density Filters (ND Filters)
If you aspire to take great-looking landscape images, you need filters. They are as essential a part of your DSLR camera kit as your tripod, or even your memory card. Back in the day, film users would rely on a catalogue of filters to provide a range of effects, from tobacco tones to soft focus. While these kinds of effects can be digitally recreated, one critical one can't, and that's neutral density. Photographers recognised that the sensitivity of film could not capture the same wide range as our eyes can see. We typically see a range of around 24 stops, while your average 35mm film could cope with between four and seven stops. This meant that in a darkened room with a bright window, where we could see detail in both window and the room, the DSLR camera would end up with either the room in complete darkness or the window completely overexposed. Similarly, on a bright day, an apparently beautiful view appears on the DSLR camera with either a white sky or dark and shadowy foreground. By using a graduated neutral density filter, photographers were able to even out the difference in brightness to levels the film could cope with and produce an image in keeping with how our eyes see it. Your typical JPEG image captured on a digital sensor offers around the same dynamic range, if not less, than 35mm film closer to the four stops of transparency film. Therefore it is even more important in digital photography to even out the brightness. Raw files do allow an increased dynamic range that can stretch to as much as 14 stops but this still pales into insignificance in comparison to human eyes.
A solid neutral density filter provides a slightly different, but equally as important, role. By reducing the amount of light to the whole image it allows the photographer to use longer shutter speeds in brighter conditions. This may be when a shallow depth of field, and therefore a large aperture, is needed, or when motion is wanted to be blurred severely for creative effect.