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There is a large selection of lenses available for SLR cameras
nowadays. You can choose from fixed focal lengths, zooms, superzooms and macro
lenses but how do you choose the right lens and what do all the different designations
that lenses have mean? This article will help know what to look for and explain
some of the jargon out there.
Different Lens Types:
Macro lenses:
A true macro lens lets you get in close enough to your subject to reproduce
it at life or half life size. Macro lenses come in a variety of focal lengths
(usually between 50mm and 200mm) and the vast majority are a fixed focal length
(not zooms).
Fixed focal length lenses:
Fixed focal length lenses are the ultimate in image quality as
they have no moving optics as in a zoom lens. Fixed focal length lenses generally
have wider maximum apertures so are perfect when shooting in low light. Big
fixed focal length telephoto lenses are a popular item in the wildlife or
sports photographers equipment list.
Zoom lenses:
The majority of lenses sold today are zoom lenses. A zoom lens
has an adjustable focal length which makes them more versatile but the image
quality isnt as good as a fixed focal length lens. A new digital SLR is most
likely to come with a standard zoom lens (something like a 18-55 or 18-70).
If you want a wider angle view (to get more of your subject into frame) then
you need a smaller number, eg 10-20 / 12-24. If you subject is at a distance
and you want to make it appear closer then you need a telephoto zoom. These
are especially useful when photographing sports or wildlife and will
have a larger focal length, eg 70-300 / 100-400. Telephoto lenses will
magnify camera shake however so it may be worth investing in a lens with a
built in image stabiliser.
Jargon Buster:
AL (Pentax) - This stands for aspherical lens which refers
to the optical elements within the lens. It will offer improved performance
and a reduction in the number of component lenses requires therefore giving
you a more compact lens.
APO (Sigma) - An APO lens has Apochromatic lens elements made
from special low dispersion (SLD) glass which produces sharper images and helps
to reduce colour aberrations.
DC (Sigma) - Sigma DC lenses have been designed to work with
digital SLR cameras with an APS-C sized sensor so are not compatible with 35mm
or full frame digital SLR cameras. Because an APS-C sized sensor is smaller
than a full frame sensor these lenses are more compact and lighter in weight
than the equivalent which is suitable for all camera types.
DG (Sigma) - Sigma DG lenses are designed for use with both
35mm or digital SLR cameras (full frame or APS-C sized sensors).
Di (Tamron) - Tamron lenses which are
suitable for both 35mm or digital SLR cameras (full frame or APS-C sized sensors.
Di II (Tamron) - Tamron lenses which
are only suitable for use with digital SLR cameras with an APS-C sized sensor.
DX (Nikon) - Nikon's range of lenses
that are only suitable for use with digital SLR cameras with an APS-C sized
sensor.
EX (Sigma) - Sigma EX lenses have superior
build and optical quality than a non EX lens.
FAJ (Pentax) - FAJ means that the lens
has auto focus but no aperture ring, therefore will not be suitable for older
manual Pentax SLR cameras.
G (Nikon) - Nikon G series lenses are
designed without a manual aperture ring therefore are not suitable for older
manual Nikon SLR cameras.
HSM (Sigma) - Stands for Hyper Sonic
Motor. Any HSM lens uses a autofocus motor driven by ultrasonic waves to give
ultra quiet and quiet AF operation. A Sigma HSM lens will also be fully compatible
with cameras without a built in AF motor such as the Nikon D40x and D60 and
will give autofocus when used on them.
IF (Sigma) - A lens with IF (Inner
Focus) doesnt change its physical length when focusing and the front element
doesnt move therefore is ideal when using creative filters as you dont keep
having to adjust the filter everytime you focus on your subject.
OS (Sigma) - Stands for Optical Stabiliser
and any lens with OS features a built in mechanism that compensates for camera
shake which allows you to get good hand held results in lower light conditions.
RF (Sigma) - RF means that the lens
has Rear Focus and will be equipped with a system that moves the rear lens group
for ultra quick and quiet autofocus operation.
SMC (Pentax) - This stands for Super
Multi Coating which is the type of coating on the optics which helps reduce
ghosting and flare.
USM (Canon) - This stands for Ultra
Sonic Motor and any lens with USM has a built in focus motor and will autofocus
quicker and quieter than a non USM Canon lens. |
