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HELPSTATIONGETMOREFROMNDFILTERS[ PHOTOGRAPHY MASTERCLASS ]Get more from
ND filters
UNDERSTAND THE PROS AND CONS OF
VARIABLE-STRENGTH ND FILTERS AND
TAKE FULL CONTROL OF LONG EXPOSURES.
[ TECHLIFE TEAM ]THE NEUTRAL DENSITY filter is a staple item in
the landscape photographer’s kit bag and a firm
favourite for creating images with energy and
depth. An ND filter is a sheet of glass or plastic
that is dyed with a pigment to reduce light
transmission, thereby darkening the scene and
allowing longer exposures. The standard filters
come in strengths of between one and four stops,
with ultra-long exposures requiring a ten-stop
model, such as Lee Filters’ Big Stopper. The
variable ND is a versatile alternative however.
These circular filters attach directly to the lens
thread and are constructed of two sheets of
polarising material. By rotating the outer ring,
light filtration can be adjusted, effectively
providing multiple filter strengths in a single unit.
This is both cost-effective and allows fine control
over exposure.
There are certain disadvantages however. If
used improperly, characteristic aberrations can be
introduced, such as a tell-tale darkening of the
image centre. In this tutorial we will explore the
best method of implementing a variable ND filter
and explain how to avoid common problems
when using these models at full strength, most
often experienced with wide-angle lenses.01
AT TACH THE FILTER
Ensure your filter is the correct size for
the filter thread of your lens. Some
models are only available in one size, so use a
stepping ring if needed to adapt the thread to the
appropriate lens diameter.03
SET FILTER DENSITY
While looking through the viewfinder or
at the LCD, rotate the filter ring to reduce
light transmission. Keep an eye on the shutter speed
and set the filter when your intended exposure value
is achieved.02
COMPOSE THE SCENE
An advantage of variable NDs is that the
image can be composed easily even with
the filter in place, unlike high-density, fixed-strength
filters. Use the optical viewfinder or LCD to arrange
your framing.DISTRACTING ABERRATION
The main disadvantage of a variable ND filter is an
incompatibility with ultra-wide lenses when used at
maximum strength, as visible in this image.BEFORE