The gold standard
Matthew Richards searches out the best upgrades for standard zoom kit lenses
Splash out on a Nikon DSLR and you generally get the option of buying a complete kit that comes with a standard zoom lens. There’s a lot to be said for the likes of the AF-S DX 18-55mm f/3.5-5.6G ED VR II for DX (APS-C) format cameras and the AF-S 24-85mm f/3.5-4.5G ED VR for FX (full-frame) bodies. They’re reasonably compact and lightweight – especially the 18-55mm, with its retractable design – and they deliver good image quality with decent all-round performance. Indeed, you can buy these DX and FX-format lenses separately for around £190/$245 and £440/$500 respectively. However, you could buy better.
One thing that all ‘kit’ lenses tend to lack is a relatively fast aperture rating that remains constant throughout the zoom range. The advantages
A standard zoom with a constant f/2.8 aperture enables you to maintain faster shutter speeds at any available focal length
are two-fold. Firstly, a standard zoom with a constant f/2.8 aperture enables you to maintain faster shutter speeds under dull lighting conditions, at any available focal length. This is typically up to two stops faster than most kit lenses at the long end of the zoom range. You’ll also get more control over depth of field, the wider aperture enabling you to blur the background more and better isolate a close-up subject in a composition. Finally, an extra bonus is that you can shoot in manual mode without worrying that the wide-open aperture might change if you adjust the zoom setting.
The downside of lenses with wider aperture ratings is that they tend to be bulkier and heavier, which can be a problem for travel photography and prolonged periods of handheld shooting. Another issue is that the outright zoom range can be comparatively limited, especially at the telephoto end. Most of the lenses we’ve chosen for this group test, in both DX and FX categories, aim to strike a compromise.
A couple of the DX-format lenses on test boost the zoom range, but have a variable aperture rating, shrinking from f/2.8 to f/4 as you extend the focal length. This is the case with the Sigma 17-70mm and Nikon 16-80mm lenses, which give ‘effective’ zoom ranges of 25.5-105mm and 24-120mm respectively.
In the FX camp, the Nikon 24-120mm and, to a lesser extent, the Sigma 24-105mm, big up the zoom range compared with the more conservative 24-70mm lenses. They retain a constant-aperture design but, this time, the widest available aperture is a narrower f/4 at all focal lengths.
It’s a sign of the times that all of the lenses on test feature optical image stabilization. Competing systems go by the name of VR (Vibration Reduction) for Nikon, OS (Optical Stabilization) for Sigma and VC (Vibration Compensation) for Tamron. The aim is the same in all cases: to automatically detect and counteract vibrations that would otherwise result in a loss of sharpness from ‘camera shake’. It’s particularly useful for handheld shooting under dull lighting conditions, typically enabling you to shoot at shutter speeds of between three and four stops slower before camera shake becomes a problem.
In other respects, the lenses on test vary considerably in terms of build quality, autofocus technology and performance, as reflected in the broad spread of prices. Let’s take a closer look at what each of the contenders have to offer.