Page 124 - (DK) Advanced Photography Guide

122 EXPLAINING | EXPOSURE CONTROL FILTERS

CONTROLLING EXPOSURE

Ambient light levels may constrain the range to achieve the amount of blurring you want
of exposure combinations that you can set on when you are shooting a moving subject.
your camera, limiting your control over the The solution is to use exposure control filters,
final image. This is particularly true of shutter which reduce the amount of light that reaches
speed, as it is often impossible to select long a camera’s sensor. Available in a range of
shutter speeds in bright light, even when the strengths, these filters are attached to your
camera’s lowest ISO is used and the lens is lens and mimic the effects of shooting
set to its smallest aperture (largest f/stop). in lower levels of light, giving you greater
This means, for example, that it can be difficult control over the level of exposure.

NEUTRAL DENSITY (ND) FILTER VARIABLE ND FILTER

Neutral density (ND) filters are available in strengths of Unlike a standard ND filter, which has a fixed strength, a
1-stop to 5-stops. Theoretically, ND filters don’t affect the variable ND filter allows you to adjust the amount of light it
colors in an image, although cheaper versions often add a lets through by rotating a ring on the filter’s frame. Being
slight magenta cast. A 1-stop ND filter halves the amount able to alter the filter’s strength is particularly useful when
of light that reaches the sensor, allowing you to double shooting video, as you can vary the degree of filtration if the
the shutter speed (or open up the aperture by one stop). light levels change while you are recording. Variable ND filters
A 2-stop ND filter quarters the amount of light that reaches can, however, make cross-shaped smears appear across the
the sensor, with the same effect on the image, and so on. image when you use them at maximum strength.
BEST FOR BEST FOR

◾ ◾ Blurring movement to create a sense of speed and/or ◾ ◾ Shooting video in changeable light conditions
reduce detail ◾ ◾ Very fine exposure control
◾ ◾ Using maximum aperture in bright conditions

US_122_123_Exp_Exposure_Filters.indd 122 05/02/2018 14:35