Lens Buyers Guide You can make dramatic improvements to your photography by choosing the right lens. Kit lenses are a convenient and affordable option, but they may not suit your particular photographic interests. In fact, the most critical factors you should consider when choosing a lens are the types of photographs you want to take and the degree of control you wish to have over how the subject is rendered.
Kit lenses usually cover popular focal length ranges, with the single-lens kit for a DX (~23 x 15 mm sensor) camera ranging from around 17-50mm. For an FX camera (36 x 24mm sensor), the typical range is 28-75mm. Kit lenses are usually built to a price and slower than prime (single focal length) lenses or fast, premium-quality zooms. If you are looking to extend the range of subjects you can photograph, develop your picture-taking skills and improve your low-light shooting capabilities for hand-held photography, you may be better off buying a different set of lenses. Alternatives to kit lenses are available from
both the camera manufacturers and a number of third-party lens manufacturers. And there’s often a wide variety to choose from, ranging from faster short zooms to all-in-one extended zooms and specialised prime lenses. Prime lenses have maximum apertures that may be up to three f-stops wider than a zoom lens of the same focal length. This provides a brighter viewfinder image, more flexibility for hand-held shooting in dim lighting and much greater control over the plane of sharpness in the picture. In this buying guide we’ll look at the most popular types of photography and discuss the best lens choices for each of them.
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Choosing a Lens for Travelling Compromises are always required when selecting lenses for a trip. You must balance portability against focal length range and somehow bring picture quality and versatility into the equation. Active travellers - and those who travel with minimum baggage - will be drawn to all-in-one zooms. For DX camera bodies, these typically cover focal lengths from 18-270mm, while buyers with FX bodies will be looking at 28-300mm lenses. AII-in-one zooms have four main advantages: - The lens stays on the camera so you never miss a shot through having to change lenses and there's minimal chance of dust or moisture getting at the sensor. - Many all-in-one zooms have excellent close-up capabilities, making them more versatile than shorter zooms. - You also require a smaller camera bag and will probably be able to use one of the convenient holster type pouches. - Only one one filter size is needed to cover all your picture-taking.
An all-in-one zoom lens lets you move between wide-
An example of an interior shot taken with a fast,
angle and telephoto shots.
wide-angle zoom lens.
But they have a few limitations buyers should be aware of: - Maximum apertures are usually smaller than short
When the weight of your camera bag isn't a prime
On the negative side, you'll need a larger camera
consideration, you can solve many of the above
bag to carry them in, which means a heavier load to carry. You'll also need to factor in issues associated
zoom and prime lenses. This means you have less
problems by taking a couple of shorter zooms or - if you
depth-of-field control when you wish to isolate
specialise in a particular type of photography - a zoom
with swapping lenses (the time taken and risk of dust
subjects from distracting backgrounds.
and a special-purpose prime lens.
entering the camera).
- These lenses are more difficult to stabilise , particularly at long focal length and macro settings. - Optical performance may be compromised and you may notice edge softness, vignetting, distortion and
Shorter zooms have three main advantages:
Prime lenses provide the best image quality and
- They are generally faster than all-in-one zooms,
widest maximum apertures. But, unless you have
particularly at longer focal length settings.
highly specific photographic goals that can be achieved
coloured fringing, particularly at the wide and tele
- Their optical performance is usually better.
with one or two lenses, you'll find it expensive to cover
limits of the zoom range .
- You can choose appropriate lenses for the main
a normal range of focal lengths without including at
subject types you shoot, selecting wider angles-of-
least one zoom lens.
view for landscape photography and longer zooms if you enjoy photographing sports or wildlife.
A 28-300mm zoom is an excellent all-in-one solution for owners of FX camera
A fast, standard zoom lens is ideal for situations where light levels are low.
bodies who want to minimise the amount of equipment they carry.
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Lenses for Landscape Photography Although just about any lens can be used for
Unless you invest in a high-quality lens, you may need
photographing landscapes, most photographers
to contend w ith the following issues :
concentrate on wide-angle lenses because they better
- Rectilinear distortion in which the sides of the image
encompass scenic panoramas. Wide zoom lenses are
bow out like the sides of a barrel. This makes it
particularly popular because they make it easier to
impossible to photograph buildings and trees with
compose shots without having to shift your position
straight verticals when they're close to the edges of the
(although this isn't necessarily the best approach).
frame. - Vignetting, where the edges of the frame are noticeably darker than the centre. - Edge softening, where the edges of the picture are unsharp while the centre is in focus . Extreme wide-angle lenses cover even more of the scene than you normally see and can lend an exaggerated perspective to your pictures. The most extreme of the wide-angles is the fish-eye lens, where rectilinear distortion is very obvious and becomes a sought-after characteristic.
A 24mm wide-angle lens comes close to replicating the natural perspective of the human eye and is a
A scenic shot taken with a focal length of 250mm
good choice when you want to avoid distortion.
showing the compression of perspective that characterises longer lenses.
But how wide should you go? The typical focal length of the human eye is around
It's also possible to photograph scenery with a
22mm (35mm equivalent), so that's the 'natural'
telephoto lens, which will provide a totally different
choice if you wish to reproduce landscapes as you
perspective. Whereas wide-angle lenses expand
see them. However, the most popular focal lengths
perspective, telephoto lenses tend to compress it,
among standard wide-angle lenses are from 10mm
making widely-separated elements in the composition
to 24mm for DX cameras and 16mm to 35mm for
An example of a scenic shot taken with a lOmm lens
appear closer together than they really are. The
FX cameras.
on a OX format camera.
illustration on this page shows an example.
Composition tips Consider the position of the horizon. Shots in which the horizon runs across the middle of the frame
Leam to shoot and stitch panoramas to cover landscapes wider than your lens can encompass.
may fail to make an impact because the viewer is
Many cameras are supplied with panorama stitching
unable to decide what is the main subject. When
software - and some cameras can even combine
composing shots, position the horizon to direct
the shots as they're taken. Panoramas are fun to
viewers' attention. If the foreground is the main
produce and can be useful in situations where you
focus, the horizon should be high ; when the sky is
don't have wide enough lenses.
more interesting, the horizon should be low.
A lO-24mm zoom lens covers an excellent range of focal lengths for landscape shots on a OX-format camera.
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Telephoto Lenses
A 70-300mm lens is an excellent general-purpose telephoto zoom that can be used for photographing family activities, sports and larger, relatively tame wildlife.
If you enjoy photographing active sports, children
photographers would consider 300mm the minimum
at play, birds and other wildlife or want to take
usable focal length , regardless of the camera they
attractive portraits, a telephoto lens is a must.
use . A 500mm focal length is even better.
Although most photographers need different focal lengths for each of these subject types, many of
One important factor to consider is the 'bokeh' (the artistic quality of the out-of-focus blurring) of the
them can be covered with a single , relatively long
lens. Differences in lens aberrations and the shape
zoom lens.
of the iris diaphragm that controls the aperture can
Unlike wide angle lenses , where a small difference in
cause some lens designs to blur the image in a way
recommended for portraiture, a powerful telephoto
focal length number can make a large difference in
that is pleasing to the eye , while others produce
zoom can deliver good results. This shot was taken
Although slightly shorter focal lengths are
angle-of-view, with telephoto lenses, shifts of lOOmm
blurring that is distracting. Attractive bokeh is
with a focal length of 270mm on a OX-format
or more in focal length provide relatively small
especially important for fast (large aperture) lenses ,
camera. Note the smooth bokeh in the background of
changes in angle-of-view. The ideal focal lengths for portraiture range from
macro lenses , and long telephoto lenses because they
the shot that doesn't distract the viewer's attention
are typically used with a shallow depth of field .
from the subject.
about 85mm to 120mm (35mm equivalent) and most photographers look for prime lenses with fast
The Value of Stabilisation
maximum apertures that enable them to isolate subjects from distracting backgrounds. However, with care, a medium tele-zoom lens (say, 70-300mm) can
Lens-shift stabilisation is the most effective method
zoom ratio, the more useful it will be. Sports and
deliver good results.
of minimising blurring due to camera shake
wildlife photographers find
and most high-quality lenses come with built-in
because they enable them to shoot at lower ISO
The requirements for photographing active sports
ve lenses indispensable
and children at play depend on how close you can
stabilisation mechanisms. An effective stabilisation
settings, thereby minimising the risk of image
get to the action and the distance range over which
system will enable you to use shutter speeds 3-4
noise. The same is true for close-up photographers
the subjects move. Here again, a medium tele-zoom
f-stops slower than unstabilised lenses.
lens (70-200mm or 70-300mm) provides enough
Anyone shooting with a zoom lens that has more
versatility for most photographers to take good shots
than 5x magnification will probably benefit from
when the action comes close and when it moves
vibration compensation (Ve) - and the higher the
because the smallest camera movements are magnified by the magnification of the lens. Examples illustrating the benefits of ve for photographing wildlife are shown in this box.
further away. Look for wide maximum apertures (f/2 .8 if possible) if you're shooting indoor sports or in low light levels. Wildlife photographers (particularly those who
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take pictures of small birds) are usually drawn to the longest lens they can afford and handle. Most •
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Macro Lenses
Although the term 'macro' is commonly used for
The 90mm focal length
close-up photography, true macro refers only to 'Iife-
provides a good working
size' reproduction - which means a 1: 1 reproduction
distance for a competitive
(magnification) ratio . If you're interested in shooting
price and is an ideal
close-ups, specialised macro lenses are available to
choice for photographers
suit all DSLR cameras.
who wish to cover a
It's quite easy to work out the maximum
wide range of close-up
reproduction ratio of a lens. Simply set the lens to
subjects. It can also be
its closest focus and focus on a ruler that shows
used for portraiture, where
millimetres. Divide the number of millimetres you
it provides a flattering
can count across the frame by the w idth of the image
and natural-looking
sensor (36 mm for 'full frame' cameras, 22 .3-23 .6
perspective.
mm for APS-C cameras). One of the most important factors in choosing a macro lens is its working distance (the distance between the front of the lens and the subject). In general, the longer the focal length of the lens,
The shorter the working distance , the more likely you
flower head works best for moderate close-ups, while
the greater the working distance it provides - but
are to encounter the following problems:
the reproductive parts (stamens, pistil) are best for
also the larger and heavier it is and the greater the
1. The subject gets 'spooked' and disappears.
extreme close-ups.
need for stabilisation and/or tripod mounting. The
2. The lens shadow interferes with the subject and
most popular focal lengths for macro lenses are 60mm, 90mm and 180mm, which typically provide approximate working distances of 20mm, 120mm and 200mm respectively.
there's not enough room to introduce artificial
Regardless of which type of lens you use, to ensure you record images with the maximum depth of field (sharpness from near to far subjects), use a small lens
lighting. 3. Focusing is difficult because depth-of-field is very
aperture and focus on the hyperfocal distance. As a
restricted .
rule of thumb, this is roughly one third of the way
For some subjects, you may want to have as much
between the closest and most distant subjects in the
of the subject as possible looking sharp. For others, it's
field of view.
an advantage to have the main subject differentiated
When shooting with a shallow depth-of-field, it's important to focus on the correct part of the subject.
from a blurred background. The subject usually dictates which strategy to adopt. Stopping down the lens is the best way to maximise
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depth-of-field. But be aware that all lenses are
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diffraction-limited; a point will come where image
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sharpness will be noticeably reduced.
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When shooting with a shallow depth-of-field, it's
How to Choose the Best Lens For a Specific Composition
important to focus on the correct part of the subject.
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For shots of insects and other small animals , the eye
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is usually the key point of focus ; for flowers, the entire
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Lens focal length table
An example of a true 1: 1 macro shot taken with the 90mm lens shown above.
Macro lenses with longer focal lengths are the most suitable for photographing highlymobile animals that are easily 'spooked'. Note the shallow depth-of-field in this image.
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