Handling and Features
Over the last year or so, Sigma have gradually been updating their lenses to fit into their 'Art', 'Sport' and 'Contemporary' lens lines. The 18-200mm range is popular amongst those who own a camera with an APS-C sensor and wish to travel light, with the convenience of a large 11.1x zoom range. This updated version includes optical stabilisation and fits into Sigma's 'Contemporary' line of lenses, which adds compatibility with Sigma's USB dock. This allows focusing adjustments and firmware updates to be applied to the lens by the user, rather than having to send it off to a technician.
This lens costs only £270, which seems very reasonable considering the specification. In this review, we'll take a look at how it performs.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Handling and Features
Weighing only 430g, this optic is lighter and slightly more compact than equivalent superzoom lenses from other manufacturers, and it is almost as small as many standard 18-55mm kit lenses. The lens balances well on the Canon EOS 7D body used for testing, and should also feel right at home on more compact entry-level camera bodies too.
High quality plastics have been used for much of the lens' construction, with a smooth matt finish that doesn't mark easily and the lens mount is made of metal. A wide rubberised zoom ring fills much of the lens barrel and the zoom action feels very smooth indeed, having just enough resistance to prevent the zoom creeping through the range when pointed downwards, however the zoom mechanism does tighten up slightly at 135mm when being zoomed in. A locking switch is provided to hold the lens at 18mm during transport.
A silent HSM focusing motor powers the focusing mechanism, resulting in fairly quick focusing. Focusing is performed internally, so the 62mm filter thread does not rotate, making this lens ideal for use with polarising and graduated filters.
Full time manual focus adjustments are not supported as the focus ring is solidly engaged with the focusing motor. Manual focus adjustments can be tricky to apply, as the focus ring is very loose, and has a very short travel from infinity to close focusing. The close focusing distance of 39cm is quite close for a lens with a zoom range like this.
Thanks to the optical stabilisation, sharp hand-held images are possible around half the time at shutter speeds as low as 1/40sec at 200mm, which is roughly three stops slower than the usual rule of thumb would dictate is possible.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Performance
At 18mm sharpness in the centre of the image area is outstanding in the centre from maximum aperture, dropping gradually due to diffraction as the lens is stopped down. Sharpness towards the edges is very good at this focal length and remains so until the lens is stopped down to f/8
Zooming to 50mm results in a slight reduction of overall sharpness. At maximum aperture the clarity in the centre is still excellent and the quality towards the edges is good. Sharpness towards the edges increases gradually as the lens is stopped down with peak quality being recorded between f/5.6 and f/11 for this focal length.
Finally, at 200mm sharpness in the centre of the frame remains very good, with clarity towards the edges falling just short of good levels. Stopping down to f/11 results in excellent sharpness in the centre and good performance towards the edges of the frame.
How to read our charts
The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Averaging them out gives the red weighted column.
The scale on the left side is an indication of actual image resolution. The taller the column, the better the lens performance. Simple.
For this review, the lens was tested on a Canon EOS 7D
Chromatic aberrations rise and fall as the lens is zoomed through the range and for different aperture values. At 18mm CA levels are quite high towards the edges of the frame when stopped down beyond f/8 and may become apparent in large prints with areas of high contrast near the edges.
How to read our charts
Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software.
Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more.
For this review, the lens was tested on a Canon EOS 7D
Falloff of illumination towards the corners is reasonably well controlled. At 18mm the corners are 1.42 stops darker than the image centre and at 200mm the corners are 1.26 stops darker. Visually uniform illumination is achieved with the lens stopped down by just over a stop from maximum aperture throughout the zoom range.
Distortion is often a weakness of high ratio zooms like this. Although the 3.3% barrel distortion at 18mm is quite strong, it isn't all that bad when compared to some similar lenses. Pincushion distortion of 1.34% is present at the telephoto end, which shouldn't pose too many issues for most. If you require completely straight lines, you'll be glad to know that the distortion pattern is uniform across the frame throughout the zoom range, which should make applying corrections in image editing software relatively straightforward.
A petal-shaped hood is supplied as standard with the lens, which does a good job of protecting the front element from extraneous light that may cause unwanted flare and loss of contrast. During testing there were no issues with flare and contrast holds up well, even when shooting into the light.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Contemporary Sample Photos
Value For Money
This 18-200mm Sigma lens includes optical stabilisation and costs around £270. Tamron's 18-200mm XR Di II costs much less at £130, but lacks optical stabilisation, which can be especially useful given the modest f/6.3 maximum aperture both lenses sport at 200mm. It also lacks the silent focusing motor, as found on the Sigma lens.
The Canon 18-200mm f/3.5-5.6 has a brighter maximum aperture at 200mm, supports full time manual focus override and also includes an image stabiliser, but costs around £100 more.
Nikon's 18-200mm f/3.5-5.6 VR II lens is much more expensive at around £560 and sports similar features to the Canon EF-S 18-200mm.
As the Sony compatible version of this Sigma lens doesn't include optical stabilisation, Sony's 18-200mm is almost exactly similar in specification, except for the Sony lens lacking a silent focusing motor. Being priced at around £400, it's around £130 dearer than this Sigma.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Verdict
Overall, this lens is a great choice for those wishing to travel light. It delivers sharp, contrasty images throughout the zoom range and costs around £100 less than comparable alternatives.
Build quality is great for a lens this inexpensive, as are focus speeds. The fact it focuses close as well, will make this lens an ideal, good value travel companion.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Pros
Good optical performance for a super zoom lens
Compatible with Sigma USB dock
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Cons
Sloppy manual focusing action with no full-time manual override
CA levels at 18mm when stopped down
|VALUE FOR MONEY
The Sigma 18-200mm f/3.5-6.3 DC Macro OS is a great choice for those wishing to travel light.
With thanks to Harrison Cameras for providing the loan of the Canon EOS 7D.
Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Contemporary Specifications
- Nikon AF
- Canon EF
- Sigma SA
- Minolta AF
- Sony Alpha
- Sony A
- Pentax KAF
|Focal Length||18mm - 200mm|
|Angle of View||8.1° - 76.5°|
|Max Aperture||f/3.5 - f/6.3|
|35mm equivalent||No Data|
|Box Contents||No Data|
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