Sigma has rightly established a reputation for building excellent-quality lenses that cost much less than proprietary versions. The company’s 70-200mm lens is by far the least costly in this group, at around £900.
Announced in September 2010, the lens is available in Canon EF, Nikon F, Sony Alpha, Pentax K and Sigma mounts, and for this test the Nikon version was used.
At 1,430g, the Sigma lens is the lightest in the group, but is still quite a weight to carry around. It is a long lens at 197mm, but it does not rotate or extend during zooming.
The zoom ring rotates clockwise from 200mm to 70mm, which matches the operation of the Canon lens, but is the opposite direction to the other three versions. Changing from 70mm to 200mm can be made in a single turn. However, the rotation of the zoom ring could do with a little more resistance, as it turns all too easily.
Unsurprisingly, given its lower price point, the overall feel of the lens is good without being class-leading. The barrel’s high-quality plastic has a smooth finish unlike any DSLR, and the lens does not feature weather-sealing like the Nikon and Canon versions.
The lens collar has a hinge, like the Tamron version. However, the collars on these lenses do not feel as sturdy, with the hinge being an added potential point of weakness under heavy use.
Supplied with the lens is a large hood measuring 107mm. Again like the Tamron lens, the hood’s interior is ridged to reduce reflections.
A simple two-switch set-up on the side of the lens is for AF/MF and stabilisation. The latter has three options: off, single-axis panning and dual-axis stabilisation.
The lens construction comprises 22 elements in 17 groups, two of which are ‘F’ low-dispersion (FLD) elements (similar to Canon’s fluorite element), and three special low-dispersion (SLD) elements. The focus group of lens elements is at the rear of the lens, hence the front-end zoom ring.
Like most of the other lenses in the group, this Sigma model offers an Optical Stabiliser that allows the use of shutter speeds up to a claimed 4-stops slower than a non-stabilised equivalent. It is, in fact, the first telephoto zoom lens from Sigma to feature stabilisation. Around eight out of ten shots were sharp when taken at 200mm and 1/30sec, which equates to around a 3EV stabilisation.
The lens uses Sigma’s Hyper Sonic Motor (HSM), which provides quiet AF (although some Pentax and Sony cameras do not support the HSM function). Autofocus speed when compared directly to the Nikon lens is not quite as responsive in all lighting conditions, but is quick nonetheless.
Image: Like the Canon lens, the bokeh of the Sigma model shows slight polygonal edges rather than being completely round
Sigma 70-200mm f/2.8 EX DG OS HSM specifications:
RRP: £1,539.99
Street price: Around £900
Filter diameter: 77mm
Lens elements: 22
Groups: 17
Diaphragm blades: 9
Aperture: f/2.8-22
Minimum focus: 1.4m
Length: 197mm
Diameter: 86.4mm
Weight: 1,430g
Lens mount: Canon EF, Nikon F, Pentax, Sigma, Sony Alpha
