creative controls
Contributory factors affecting depth of fi eld
Depth of fi eld is also affected by the distance the photographer is positioned from the subject and
by the focal length of the lens being used.
Distance- As the photographer moves closer to the subject the depth of fi eld becomes narrower.
As the photographer moves further away the depth of fi eld becomes greater.
Focal length - As the focal length of the lens increases (telephoto lenses) the depth of fi eld
becomes narrower. As the focal length of the lens decreases (wide angle lenses) the depth of fi eld
becomes greater.
The narrowest depth of fi eld is achieved with the widest aperture on a telephoto
lens whilst working at the lenses minimum focusing distance.Point of focus - Unless you are very close to your subject, you’ll fi nd that depth of fi eld, your
acceptable focus range, extends more behind the subject than in front. About twice the distance
behind your point of focus will be in focus than in front of it.
Practical application
All factors affecting depth of fi eld are working simultaneously. Aperture remains the photographer’s
main control over depth of fi eld as framing (usually a primary consideration) dictates the lens and
working distance. For maximum control over depth of fi eld the photographer is advised to select
aperture priority or manual mode and use a DSLR camera. Firstly decide on the subject which is
to be the focal point of the image. Second decide whether to draw attention to this subject, isolate
the subject entirely or integrate the subject with its surroundings. Precisely focusing the lens is
unnecessary when photographing in bright conditions with small apertures (f11, f16 and f22). Depth
of fi eld on a wide angle lens stopped down to f16 may extend from less than one metre to infi nity.
Mark Galer