The primary reason for choosing a new lens is to enjoy a broader or alternative focal range. All four lenses in this Nikkor group test offer general-purpose ranges from wide angle to telephoto. While all start at a focal length of 18mm though, the major difference between them is how much they can zoom in.

When zoomed-in, the Nikkor DX 18-55mm II, DX 18-70mm, DX 18-135mm and DX 18-200mm VR lenses each offer equivalent focal lengths of 83, 105, 203 and 300mm respectively. Clearly that’s a big difference in practice and one we’ll illustrate in a moment. But first we’ll compare the coverage of each lens when zoomed-out to wide angle; they may all quote a shortest focal length of 18mm (equivalent to 27mm on a Nikon DSLR), but in practice there can be slight differences.

To compare their actual coverage in real-life we shot the same scene with each lens within a few moments of each other from a tripod to ensure a consistent position. Below are resized samples from each lens set to its widest focal length.

Nikkor DX 18-55mm II		Nikkor DX 18-70mm		Nikkor DX 18-135mm		Nikkor DX 18-200mm
18-55mm at 18mm (27mm equiv)		18-70mm at 18mm (27mm equiv)		18-135mm at 18mm (27mm equiv)		18-200mm at 18mm (27mm equiv)

The samples above may look identical, but with each image examined at their original size, one difference is apparent: the budget DX 18-55mm II lens captures a fractionally smaller field than the other three lenses when zoomed-out to wide angle. It is a very small difference though and nothing to be overly concerned about – certainly it’s a smaller difference than that found between different Canon lenses quoting a 17mm focal length – see our Canon kit lens group test.

Now onto telephoto coverage with each lens zoomed-in to its longest focal length; once again we shot the same scene with each lens within a few moments of each other from a tripod to ensure a consistent position. Below are resized samples from each lens set to its longest focal length.

Nikkor DX 18-55mm II		Nikkor DX 18-70mm		Nikkor DX 18-135mm		Nikkor DX 18-200mm
18-55mm at 55mm (83mm equiv)		18-70mm at 70mm (105mm equiv)		18-135mm at 135mm (203mm equiv)		18-200mm at 200mm (300mm equiv)

As clearly seen in the samples above, each lens delivers a progressively smaller field of view. The jump from 55 to 70mm may be quite modest, but at 135mm you’re significantly closer to the subject; the DX 18-135mm offers more than double the magnification of the basic DX 18-55mm II kit lens and much greater flexibility in practice. Clearly the DX 18-200mm offers the greatest range and flexibility of all here, along with Vibration Reduction facilities to reduce camera-shake which we’ll test below.

Nikkor DX kit lens group test aperture

After focal length, the most important specification of a lens is its aperture. All but the DX 18-70mm offer a focal ratio of f3.5 at wide angle and f5.6 when zoomed-in; these are fairly average and nothing to get particularly excited about. The DX 18-70mm also has a focal ratio of f3.5 when zoomed-out to 18mm, but boasts a slightly brighter focal ratio of f4.5 when zoomed-in – that’s about 2/3 of a stop brighter than the others and gives a slight edge in low light performance. If you’re really serious about low-light work though, you should consider investing in an optically ‘faster’ model like the Nikkor DX 17-55mm f2.8.

Nikkor DX 18-200mm Vibration Reduction

The unique selling point of the Nikkor DX 18-200mm over the other lenses here is the inclusion of Vibration Reduction (VR) technology to combat camera-shake. The DX 18-200mm was the first Nikkor lens to feature its latest second generation VR II, which according to Nikon delivers four stops of compensation, compared to the three stops of the former VR system - and it has to be said the three stops also offered by Canon's current IS system. Four stops is a significant claim, which if true would allow you to handhold shutter speeds a considerable 16 times slower than normal.

VR is enabled by an on / off switch on the side of the lens, and kicked-into action by a half-press of the shutter release button. As with other lens-based stabilisation systems, there's a faint click after which the composition through the viewfinder appears to steady itself and float gently. The system deactivates with another faint click moments after lifting your finger from the shutter release, and the shakiness returns to the viewfinder. A second switch on the side of the barrel alternates between Normal and Active mode, the latter only correcting the vertical Y-axis for use when panning with moving subjects like passing aeroplanes or runners.

To illustrate the effect of VR in practice we've presented two crops below of a scene taken with and without VR enabled using a focal length of 200mm and a shutter speed of 1/15. We've cropped the original 4288x2848 images taken with a Nikon D2X to 1680x1120 pixels, then reduced them to 282x188 pixels here. The benefit is clear, and even when viewed at 100%, the shot with VR is perfectly sharp. Note VR, like other anti-shake systems, won't freeze a subject in motion, so the jogger in the crop below left would still have been blurred in a 1/15 exposure even with VR activated.

Nikkor 18-200mm without VR		Nikkor 18-200mm with VR
Nikkor 18-200mm VR at 200mm (300mm equivalent). VR disabled. 100 ISO, 1/15th second		Nikkor 18-200mm VR at 200mm (300mm equivalent). VR enabled. 100 ISO, 1/15th second