Digital Camera World » wide angle lens

Wide angle portraits: how to use your wide-angle lens to caricature your friends

jmeyer — Thu, 21 Mar 2013 16:40:35 +0000

Did you think your wide-angle lens was just for landscapes? Think again! Find out how to take wide angle portraits that will wow your friends and family.

If your wide-angle lens only comes out for landscape shots, you’re not fulfilling its potential. Try using it for portraits for fantastically distorted results – your wide lens will turn your friends into cartoon versions of themselves.

Wide angle portraits play on the natural distortion that wide lenses produce. ‘Barrel’ distortion causes otherwise straight lines to appear bulged if they don’t pass through the centre of the image.

This effect is more marked at the edges of the frame, and barely noticeable in the centre of the shot. Normally you’d avoid distortion, but by exaggerating the effect you can create a caricature-style shot.

Just choose a wide-angle lens, and find a subject who doesn’t mind being experimented on!

How to shoot wide angle portraits

01 Switch to a wide-angle lens
When it comes to distorting reality, the wider your lens the better, so a 10-20mm super-wide-angle lens is ideal. You could use an 18-55mm kit lens, but the distortion won’t be as pronounced and you’ll need to exaggerate your angles even more to get a cartoon-like look.

02 Choose an urban backdrop
Think about your surrounding environment. You won’t get a shallow depth of field with a wide-angle lens, so a distracting or busy background can take away focus from your subject if you aren’t careful. Choose a plain wall or an urban setting to keep things simple.

03 Vary your point of view
Experiment with angles for different effects, while always staying close to your subject. Placing the centre of a face in a corner of the frame will make features look disproportionately huge, while extremities like hands and feet that are further from the lens will look weirdly small.

Free Cheat Sheet: what your camera captures at every lens’ focal length

jmeyer — Fri, 07 Sep 2012 15:01:04 +0000

Knowing how much of your scene you can capture at each lens’ focal length is a conundrum every photographer has come up against.

In our earlier post earlier answering the question, ‘What is Focal Length?,’ we looked at some of the differences and capabilities of using a telephoto vs wide-angle lens.

A wide-angle lens exaggerates perspective, while using a telephoto lens gives the effect of compressing perspective, bringing elements closer together in the frame.

In the latest of our ongoing photography cheat sheet series we aimed to illustrate some of the differences a different lens focal length can have both in terms of how your image looks and how much of your scene your camera is able to include.

In our infographic below you can see just how much of a scene your camera can capture at different focal lengths starting from an ultra-wide 10mm all the way up to 400mm.

To see the larger version of this photography cheat sheet simply click on the image below, or drag and drop it on to your desktop.

How different types of lenses ‘see’ the world

jmeyer — Fri, 29 Jun 2012 01:00:11 +0000

There are many different types of lenses available to photographers, as we all know, and the type of lens you choose to fit on your SLR will determine how your end results will look.

The main consideration is focal length. Focal length is the distance between the optical centre of a lens and the sensor, but it’s easier to think in terms of how this affects subject size when compared with a standard lens. For a camera with a full frame sensor, a standard lens is 50mm.

The types of lenses with focal lengths shorter than 50mm are known as wide-angles, while lenses with focal lengths longer than 50mm are referred to as telephotos.

Which type of lens you need will depend on the subject you are shooting, but most focal lengths offer creative potential with all subjects.

Below we’ve broken down the different types of lenses for you to choose from and explain what they’re typically used for and the effects you can expect from them.

We’ve also included images taken with each of these types of lenses to show you the many different effects they produce when shooting the same subject.

At the top left of this page we’ve also included an infographic combining the effects from all the types of lenses into one cheat sheet. The graphic shows the effects of shooting the same subject with different types of lenses. To download the larger version of this cheat sheet, simply drag and drop it on to your desktop.

And if you liked this, you can click here to find more from our photography cheat sheet series.

Shot with a fisheye lens

Fisheye lenses
Fisheye lenses (8-16mm) differ from conventional lenses in that they produce images with a slightly curved or bowed appearance, and a field of view that covers up to 180 degrees.

Shot with an ultra wide-angle lens

Ultra Wide-angle lenses
Ultra wide-angle lenses fall in the 10-24mm range and have a very wide angle of view, which allowsyou to work very close to your subject and stillinclude it all in the frame.

Shot with a wide-angle lens

Wide-angle lenses
A typical wide-angle lens falls between 24-35mm, and is often incorporated into a wide-angle kit lens in the 18-55mm range, or it can be a fixed focal length prime lens.

Shot with a standard lens

Standard lenses
A standard lens is 50mm for DSLRs with a full frame sensor. The equivalent focal length for crop-sensor cameras lies in the 28-35mm range, dependingon the camera model.

Shot with a short telephoto lens

Short telephoto lenses
Lenses in the 100-200mm range are known as short telephotos. They are used for isolating specific subjects within landscapes, and for portraits and close-up work.

Shot with a long telephoto lens

Long telephoto lenses
Long telephotos typically have a focal length of 300-600mm and have a very narrow angle of view, making them the lens of choice forwildlife and sports photography.

Canon boosts EF lens range with three new models

jmeyer — Tue, 07 Feb 2012 17:13:15 +0000

Canon has announced three new EF lenses to add to its range, a 24-70mm f/2.8 ‘L’ series lens is joined by 24mm and 28mm fixed focal length prime lenses.

First up, the new EF 24-70mm f/2.8 L II USM lens is added to Canon’s professional line and is an upgrade to the previous standard zoom lens.

It features a redesigned optical system which includes two Ultra-low Dispersion (UD) and one Super UD aspheric element which is designed to minimise chromatic aberration and colour blurring.

Super Spectra coatings to reduce ghosting and flare have also been included, along with a fluorine coating to minimise the amount of dust, dirt and fingerprints.

A ring-type Ultrasonic Motor (USM) works in combination with a high-performance CPU for quick and accurate, and silent autofocus. The lens has a minimum focusing distance of 0.38m at all focal lengths throughout the zoom range.

The structure of the lens has been improved to offer enhanced zoom durability along with grater shake and shock resistance within the barrel. The size of the lens has also been reduced by 10mm.

A new zoom lock lever means that photographers can lock the zoom position at the extreme wide end of the lens to prevent damage to the lens in transit, while it is also water and dustproof.

Read more about the new Canon EF lenses, on our sister website, TechRadar.

Tamron unleashes 24-70mm f/2.8 standard zoom

jmeyer — Tue, 07 Feb 2012 11:40:47 +0000

Tamron has announced a new fast, 24-70mm f/2.8 standard zoom lens, which is available in mounts compatible with Sony, Nikon and Canon DSLRs.

The new lens comes equipped with Tamron’s Vibration Compensation (VC) image stabilisation and Ultrasonic Silent Drive, which is designed to help when shooting handheld.

Tamron’s lens also uses special high-grade glass in three LD elements, along with three glass molded aspherical lenses, one hybrid aspherical lens and two XR (Extra Refractive Index) glasses. It also incorporates a rounded diaphragm to enhance out of focus areas, which retains a nearly circular shape even hen taken two stops down from its fully open state.

Full specs for the moisture-resistant Tamron 24-70mm f/2.8:

Model:                        A007
Focal length:                    24-70mm
Maximum aperture:                F/2.8
Angle of view (diagonal):            84°04’ －34°21’ (for full frame 35mm format cameras)
60°20’ －22°33’ (for APS-C format cameras)
Lens construction:                17 elements in 12 groups
Minimum focus distance:            0.38m (15.0 in)
Maximum magnification ratio:        1:5 (at f=70mm: MFD 0.38m)
Filter size:                    φ82mm
Length:                        108.5mm*
Entire Length:                    116.9mm*
Diameter:                    φ88.2mm
Weight:                        825g*
No. of diaphragm blades:            9 (rounded diaphragm)
Minimum aperture:                F/22
Standard accessories:            Flower-shaped lens hood
Compatible mounts:            Canon, Nikon, Sony

Choosing a lens

crutter — Thu, 08 Dec 2011 11:03:56 +0000

Most of us start off with a cheap everyday lens when we get into digital photography. The kit lenses that come bundled with camera bodies are versatile workhorses, with decent zoom ranges that will be useful in most photographic situations. However, there will come a time when you want to add to your creative equipment, and expanding your collection of lenses is a great way to do this. The lens you opt to put on your SLR is one of the most important creative decisions you can make. Other than the sensor, it will have the greatest influence over the quality of your images. Here’s a brief introduction to some of the key things you need to consider when choosing a new lens.

Crop factor

The size of your SLR’s sensor affects the angle of view of your lens – the smaller the sensor, the longer the ‘effective focal length’. A ‘full-frame’ sensor, as used in the Canon EOS 5D mark II or Nikon D700, has the same physical dimensions as a frame of 35mm film, but smaller ‘APS-C’ sensors, as used in the majority of entry-level and mid-range SLRs, capture a smaller proportion of the image projected by the lens. This has the effect of increasing the effective focal length by a factor of 1.5x or 1.6x (depending on the manufacturer). On a camera with an APS-C sensor, a 50mm lens effectively provides an angle of view equivalent to a 75mm or 80mm lens on a full-frame or 35mm film camera. This is great news if you want to shoot wildlife or sports, because a 400mm lens effectively becomes a 600mm or 640mm lens. However, it means that for serious wide-angle work, you need to use an ultra-wide lens – which is why lenses such as the Sigma 10-20mm are popular with landscape photographers who use cameras with APS-C sensors.

Lens speed

We’re not talking focusing speed here, but rather the light-gathering capability of the lens. ‘Fast’ lenses have wide maximum apertures, such as f/1.4 or f/2.8, and so on. They let in more light at this aperture than lenses with maximum apertures of, say, f/4 or f/5.6, which enables you to achieve faster shutter speeds without increasing the ISO. The downside is that they are heavier and more expensive. With ‘slower’ lenses you may need to increase the camera’s ISO in order to get sharp shots in low light. The speed of a lens is also relative to its focal length – a 500mm f/4 lens is considered fast, whereas a 100mm f/4 lens is considered slow. The wide maximum apertures of fast lenses also enable you to achieve a shallower depth of field in your pictures – great for portraits, sport and wildlife.

Floating or fixed aperture?

Another factor that determines the cost of a zoom lens is whether it maintains the same maximum aperture (f/2.8, for example) throughout the zoom range (more expensive) or if the aperture gets smaller (f/4-5.6, for example) as you zoom from wide to long focal lengths (cheaper). The downside of so-called ‘floating’ apertures is that in order to maintain the same exposure, the shutter speed needs to be decreased as the aperture gets smaller.

Five lenses worth saving for…

Telephoto zoom

A telephoto lens is an optic with a focal length of over 70mm. ‘Tele’ means ‘far off’ in Greek, so telephoto lenses make far-off subjects seem closer than they really are. They also compress perspective.

Wide-angle

Anything within the 10mm to 24mm range is considered to be a wide-angle lens (on APS-C SLRs), which makes wide angles a natural choice for landscapes and shots taken indoors.

Macro

True macro lenses will enable 1:1 magnification in close-up photography, so subjects appear life-size on the sensor. This means that you can fill the frame with objects that are an inch or two wide.

Prime

Prime lenses have fixed focal lengths (which means they can’t be zoomed). They tend to have fast maximum apertures and are generally of superior optical quality compared with zoom models.

Superzoom

Superzooms offer an enormous range of focal lengths (such as 18-200mm) in a single lens, which makes them ideal for travel photography. The downsides include narrower apertures and inferior quality.

Back to: Focus modes explained

Forward to: Flash modes explained

Superzoom lenses group test

dcworld — Tue, 13 Apr 2010 14:48:12 +0000

Fit a superzoom lens to your DSLR and you’ll be prepared for almost any shooting situation. Find out which one’s for you in our superzoom lens review.

One of the main attractions of a D-SLR over a compact is that you can swap lenses on demand. But there’s a catch or two. Most digital photographers prefer to change lenses as little as possible, to avoid dumping dust on the sensor.

And if you’re on holiday, travelling or just walking around, wouldn’t it be nice if you could replace a whole gadget bag full of lenses with just one do-it-all lens? That’s where a superzoom comes in.

Superzoom lenses have been around for decades, but historically, these 28-200mm or 28-300mm beasts have been fraught with compromises. Older models were often big and bulky, and offered mediocre optical quality. More recently, manufacturers have made huge strides, increasing sharpness and contrast and reducing unwanted side-effects such as chromatic aberrations (colour fringing), ghosting and flare. It’s all thanks to the use of computer-designed aspheric elements, high-tech lens coatings and precision-engineering methods.

All the lenses in this test group are specifically designed for D-SLRs with APS-C sensors, rather than full-frame cameras, so another bonus is that you can expect to get a generous telephoto reach neatly wrapped in a relatively small and lightweight package.

The maximum apertures at telephoto settings still tend to be a little slow, making camera shake a potential problem, but most of the latest examples feature built-in image stabilisation (IS) as well, giving them every chance of making great all-rounders.

Canon EF-S 18-135mm f/3.5-5.6 IS

Price: £400

(Street)

Supplied as a kit lens with the new EOS 7D, the EF-S 18-135mm IS looks low-tech compared with Canon’s high-performance, semi-pro body. The somewhat basic design lacks USM (UltraSonic Motor) autofocus and the standard micro-motor fitted is comparatively noisy. Build quality is a step up from canon’s most basic ‘kit’ lenses. For example, the mounting ring is metal rather than plastic.

However, out of two samples of this lens, one had almost no zoom creep at all while the other suffered quite badly, a problem made worse by this being the only lens in the group not to feature a zoom lock switch. The latest-generation Image Stabilizer lived up to its four-stop promise in our tests and the upside of the modest 7.5x zoom range is that distortions are less of an issue than with some super-zooms.

Sharpness was pretty good and, again, rather better than with the previous sample of this lens that we’ve seen, which raises questions about manufacturing consistency.

Ratings:

Features – 3/5
Build Quality – 3/5
Handling – 4/5
Image quality – 4/5
Value for money – 4/5

Verdict:

With only a basic set of features and questionable consistency in build quality, this lens seems a little over-priced. 80%

Canon EF-S 18-200mm f/3,5-5.6 IS

Price

: £480 (street)

At first glance, there’s little difference between this lens and Canon’s cheaper EF-S 18-135mm model. Both have an identical layout of Image Stabilizer and AF/MF switches and the zoom and focus rings are almost the same, although the focus ring is a little narrower on the 18-200mm.

They’re also almost exactly the same length when used at the 18mm end, although the 18-200mm is more than ready to extend itself under the force of gravity, so the zoom lock switch is a worthwhile addition. As with the ower-powered Canon in the group, there’s no finery, such as USM autofocus or a focus distance scale, and the overall build looks and feels rather basic.

The trade-off of having the extra zoom range is that distortions are more noticeable and there’s a little more chromatic aberration (colour fringing), but at least these are fairly easy to minimise if you shoot in RAW and use the Digital Photo Professional software that comes bundled with Canon Cameras.

Ratings:

Features – 3/5
Build quality – 3/5
Handling – 4/5
Image quality – 4/5
Value for money – 4/5

Verdict

: Features and performance aren’t captivating at the price and even the lens hood costs extra. 83%

Nikon 18-200mm f/3.5-5.6G AF-S DX ED VR II

Price

: £590 (street)

Nikon launched its original 18-200mm AF-S VR back in 2006, but the newer ‘VR II’ edition boasts four-stop rather than three-stop Vibration Reduction, improved lens coatings and a zoom lock switch. As it turns out, zoom creep is much less of an issue than with the original lens, which would go into freefall between focal lengths of 24mm and 135mm, and both models generally stay firmly in place at 18mm.

Despite having an RRP that’s £10 less than Canon’s 18-200mm, the Nikon has plenty of extra goodies, including super-fast, practically silent AF-S autofocus complete with full-time manual override, switchable Normal/Active VR modes, a focus distance scale neatly positioned beneath a viewing window and better-feeling build quality all round.

Optically, the Nikon proved not only to be the sharpest lens on test, but also retained its sharpness better at maximum apertures throughout the zoom range.

Ratings:

Features – 5/5
Build quality – 5/5
Handling – 5/5
Image quality – 4.5/5
Value for money – 4/5

Verdict

: This is simply the best superzoom for Nikon users, even if it’s more than twice the price of some lenses on test. 94%

Sigma 18-125mm f/3.8-5.6 DC OS HSM

Price

- £240 (street)

The Sigma 18-125mm is wonderfully compact, and at just £240 it’s also the cheapest lens in the group. The catch is that the zoom range is also the smallest, but you still get a useful 29-200mm effective reach on a Canon body, or 27-187mm on a Nikon.

Along with a very high standard of finish, the lens features Sigma’s latest four-stop OS (Optical Stabilizer) system, which works a treat, as well as super-quiet and reasonably rapid HSM (Hypersonic Motor) autofocus. There’s a lot to love here.

The Sigma’s optics aren’t quite as sharp as the Nikon’s, but they’re impressive nonetheless. Distortions and chromatic aberrations are well controlled, helped by the relatively meagre zoom range. Zoom creep in our test sample was non-existent, although you still get a zoom lock switch for good measure.

Unless you really need the extra telephoto reach offered by the bigger lenses in the group, the Sigma 18-125mm makes an excellent choice for a wide range of camera makes and models.

Ratings:

Features – 4.5/5
Build quality – 4.5/5
Handling – 4.5/5
Image quality – 4/5
Value for money – 4/5

Verdict:

A highly accomplished lens in all respects. The only downside is that it has the smallest zoom range in the group. 90%

Sigma 18-200mm f/3.5-6.3 DC OS

Price

- £290 (street)

One of the very first lenses that Sigma produced with its proprietary OS (Optical Stabilizer) system, the 18-200mm is starting to show its age. Unlike other stabilised lenses in the group, you only get a three-stop rather than a four-stop benefit and you don’t get Sigma’s refined and near-silent HSM autofocus system, similar to Canon USM and Nikon AF-S.

Then again, Canon’s USM autofocus isn’t featured on either of its superzoom lenses, so the Sigma still has potential at just half the price of the equivalent Canon 18-200mm. Build quality feels good overall, but our review sample had a little zoom creep, about the same as with the Nikon 18-200mm, but much less noticeable than on the Canon 18-200mm.

Optical quality was also a notch down from the other Sigma lenses in the group, with less sharpness and contrast, while chromatic aberrations were rather more noticeable, with colour fringing frequently adorning high-contrast edges of objects within scenes.

Ratings –

Features – 4/5
Build Quality – 4/5
Handling – 3.5/5
Image Quality – 3/5
Value for Money – 3.5/5

Verdict

: The price is attractive for a stabilised 18-200mm lens, but with mediocre image quality, this isn’t our first choice. 79%

Sigma 18-250mm f/3.5-6.3 DC OS HSM

Price:

£400 (street)

A major step up from Sigma’s older 18-200mm lens, this features Sigma’s new-generation four-stop Optical Stabilizer plus you get HSM autofocus, which is quick and all but silent.

Then there’s the mightier zoom range, which is almost on a par with the Tamron 18-270mm. For a superzoom lens with such a big range, the Sigma does an excellent job of combining silky-smooth zoom ring operation with zero zoom creep, and the manual focus ring is similarly smooth and precise, even if it lacks the Nikon’s trick of enabling full-time manual focus override when you’re in autofocus mode.

Optically, the Sigma 18-250mm proved very convincing in our tests, with excellent sharpness, contrast and colour rendition, while distortions were reasonably well contained and resistance to ghosting and flare was also impressive.

Considering it’s much cheaper than the Canon or Nikon 18-200mm lenses, and 60 cheaper than the Tamron 18-270mm, this really is an excellent buy at the price.

Ratings

Features – 4.5/5
Build quality – 5/5
Handling – 5/5
Image quality – 4.5/5
Value for money – 4.5/5

Verdict:

A cracking lens at the price, with excellent handling and reassuring build quality, along with a monster zoom range. 92%

Tamron 18-250mm f/3.5-6.3 Di II Macro

Price

: £390 (street)

This lens was something of a revelation when it was first launched, being almost identical in size and weight to Tamron’s older 18-200mm lens, yet offering a more generous zoom range and better image quality.

Indeed, sharpness and contrast are pretty much as good as almost any other lens in this group. Build quality is also impressive, and zoom creep is only an issue when using the 50-100mm focal range.

The major drawback is that, unlike every other lens on test here, the Tamron 18-250mm lacks an image stabiliser. Coupled with a relatively slow maximum aperture of f/6.3, this makes the effective telephoto reach of around 400mm almost impossible to utilise without increasing your camera’s ISO to fend off camera shake in anything other than the brightest lighting conditions.
Autofocus is only based on a standard micro-motor as well, making the Tamron look poor value compared with the Sigma 18-250mm OS HSM.

Ratings

Features – 3/5
Build quality – 3.5/5
Handling – 3.5/5
Image quality – 4.5/5
Value for money – 3/5

Verdict:

Optical quality is great but lack of image stabilisation makes it hard to use the lens’s reach without a tripod. 80%

Tamron 18-270mm f/3.5-6.3 Di II VC Macro

Price

- £460

For sheer zoom power, this lens rules the roost with its amazing 15x range. It also features Tamron’s VC (Vibration Correction) stabilisation system, which matches the latest Canon, Nikon and Sigma equivalents by offering a four-stop anti-shake advantage. This makes this lens much easier to use at longer telephoto lengths comparedwith Tamron’s older 18-250mm.

Distortions aren’t too bad considering the huge zoom range, and sharpness and contrast are extremely good,although chromatic aberrations are marginally more prevalent than usual. There’s little to choose between this lens and the Sigma 18-270mm, but the Tamron’s basic micro-motor autofocus system is noisier and its zoom ring is a little stiff and uneven by comparison.

Another slight curiosity is that Tamron sticks a ‘Macro’ badge on both its xuperzoom lenses, even though they’re really not macro lenses and merely offer about the same maximum magnification factor as other lenses on test.

Ratings

Features 4.5/5
Build quality – 4/5
Handling – 4/5
Image quality – 4.5/5
Value for money – 4/5

Verdict

: Very good optical quality and the mammoth 15x zoom range is unbeatable, but there’s still room for improvement.

To see test shots from the superzoom group test, buy this month’s (Spring 2010) issue of Digital Camera Magazine, on sale now.

Lens Review: Nikon 55-200mm F/4-5.6G AF-S VR DX IF-ED

dcworld — Fri, 22 Jan 2010 14:31:49 +0000

Lens reviews: the Nikon 55-200mm offers some neat tricks, but does it lack reach?

The 55-200mm AF-S VR – Nikon’s closest competitor to Canon’s EF-S 55-250mm IS lens – is a ‘DX’ model for APS-C cameras, though it can also be used in ‘crop’ mode on most full-frame Nikon D-SLRs. There are some notable similarities and diferences to the Canon offering. Firstly, the build quality is pretty much the same, with a reasonably sturdy but plastic construction, including a plastic lens mount.

Also, like the Canon, this Nikon lens lacks a focus distance scale. On this lens the manual focus ring looks almost like an afterthought tacked on to the front end of the lens. As well as its small size, the focus ring has very high gearing, making it diicult to use for accurate manual focusing.

Switch to autofocus and the Nikon fares massively better, with a super-quiet, highly accurate AF-S (AF Silent Wave) system that’s a major improvement over Canon’s more humble micro motor. The three-stop stabiliser isn’t the latest and greatest, but it’s pretty efective nonetheless.

The only really limiting factor in this Nikon is its outright telephoto reach, which works out to 300mm when you take the 1.5x crop factor into account. By comparison, the Canon’s 1.6x crop factor puts the EF-S 55-250mm to a much more generous 400mm.

Even so, there are still a couple of extra pluses for the Nikon, as it comes with a hood and soft pouch, which you have to pay extra for when buying most Canon lenses.

Sigma 10-20mm f/4-5.6 EX DC HSM Lens review

dcworld — Tue, 13 Oct 2009 12:37:31 +0000

An ultra-wide angle lens at a cheap price, but will it deliver?

The Sigma 10-20mm f/4-5.6 is the cheapest lens in the group. The respectable 10-20mm zoom range is equivalent to 15-30mm on 1.5x crop factor cameras like Nikon and Pentax, and 16-32mm on a Canon body.

It’s available in all the same mounts as Sigma’s new, constant-aperture version of the lens, as well as in Olympus Four Thirds mount (although the effective zoom range of 20-40mm is less impressive at the ultra-wide end on Olympus cameras).

The Hypersonic Motor (HSM) autofocus system isn’t blindingly fast but proved highly accurate and whisper-quiet in our tests. The lens is also very smartly turned out, belying its modest price and featuring the texture black finish favoured by Sigma’s EX series lenses. As with other Sigma lenses, it comes complete with dedicated hood and a high-quality carrying pouch that’s worth having.

The two ELD elements of the newer Sigma 10-20mm lens on test are missing from the older version. The line-up is instead built around three SLD elements and three aspherican elements. On paper, this looks inferior but, in our tests, the lens performed as well as Sigma’s more expensive counterpart and, although sharpness was a lacking when shooting wide open, the optics sharpened up nicely at f/8.

Sigma 10-20mm f/3.5 EX DC HSM

dcworld — Tue, 13 Oct 2009 12:27:48 +0000

We put one of Sigma’s ultra-wide angle lenses through its paces.

Sigma’s newest 10-20mm lens is bigger and heavier than the other Sigma model, also tested here. It features a larger front elements that requires an 82mm filter thread, whereas most lenses in the group only need 77mm filters.

Both Sigma lenses use the company’s HyperSonic Motor (HSM) autofocus, which is practically as quiet as the equivalent Canon and Nikon systems, although it proved rather slower in our tests. Full-time manual focus override is available in all the lens’s mount options, which include Canon, Nikon, Pentax, Sigma and Sony.

The biggest bonus of the new Sigma 10-20mm lens is that it has a constant maximum aperture of f/3.5 throughout the zoom range. This is very slightly faster at 10mm and just over a stop faster at 20mm. For our money, however, this alone doesn’t warrant the additional £210 cost over Sigma’s other model, as overall image quality didn’t prove noticeably better.

There’s quite a feast of glassware inside the new Sigma 10-20mm lebs, including one Special Low Dispersion (SLD), two Extraordinary Low Dispersions (ELD) and four aspherical elements. There are also Super Multi-Layer lens coatings to reduce ghosting and flare but, overall the Sigma lacked sharpness when shooting wide open, making its reasonably fast constant aperture less of an attraction in practical terms.