Nikon Owner Issue 21
All-in-one Wonder
Simon Stafford takes a close look at the AF-S VR DX 18-200mm f/3.5-5.6G the wide-range zoom for Nikon's D-SLR cameras. All words and pictures by the author.
The AF-S VR Zoom-Nikkor DX 18-200mm f/3.5-5.6G IF-ED is the latest edition to Nikon's range of lenses designed specifically for their digital SLR cameras. Its specification suggests it might be the perfect all-round lens. Simon Stafford takes a close look.
If the D200 was the worst kept Nikon secret of 2005 then the introduction of the AF-S VR Zoom-Nikkor DX 18-200mm f/3.5-5.6G IF-ED lens was probably the best, which is all the more surprising since they were announced on the same day.
When I first heard about this new Nikkor some months before the official launch I had to re-read the specification to check that I was not daydreaming! Nikon are no strangers to producing high-ratio zoom lenses but such a lens that also incorporated silent wave Auto-Focus (AF-S), Vibration Reduction (VR), Extra-low dispersion (ED) glass, all wrapped up in a small, compact package for the DX-format digital SLR cameras sounded too much to hope for, particularly if its performance matched the specification I thought it probably would be, based on my less than favourable experience with previous lenses of a similar design. I am utterly delighted to say my scepticism was totally misplaced - Nikon have pulled off a remarkable feat of optical engineering.
Nomenclature
Before I get to the hands-on part of this review let me start by extracting a few sections of its full title to help define its principal features:
AF-S (Auto-Focus - Silent wave) - the lens has a built-in focusing motor that converts linear wave energy into a rotational force to drive the focusing action near silently at high speed, and with great precision for improved focus accuracy.
VR (Vibration Reduction) - the lens incorporates a number of motion sensors that detect vibration of the lens, such as that induced by hand-holding the camera (camera shake). A series of motors shift a specific group of lens elements in response to signals received from these motion sensors to counter the effect of this movement, which is particularly useful when you want to shoot at a shutter speed below one you would normally use for hand-held photography. It is important to understand that VR can only reduce the effect of camera shake; it can have no affect on subject movement (i.e. for static subjects using a relatively slow shutter speed has no consequence but if the subject is moving it is likely it will appear blurred).
DX (DX-format) - the DX-format sensor used in Nikon D-SLR cameras is smaller than a 35mm film frame. As such DX-type lenses can be designed to be smaller and lighter than their 35mm counterparts, because the image circle DX-type lenses project covers a smaller area.
Specification
The size of this lens belies its optical performance - considerably smaller than the DX 17-55mm f/2.8G but not that much larger than the DX 18-70mm f/3.5-4.5G, it weighs in at a very modest 560g (19.8oz). The focal length range of 18-200mm offers an angle of view from 8° to 76° on the DX-format sensor (equivalent to 28mm - 300mm on a 35mm film camera). It has a variable maximum aperture of f/3.5 to f/5.6 (minimum aperture is f/22), and comprises 16 elements in 12 groups (three aspherical and two Extra-low dispersion glass elements). The minimum focus distance, which is available at all focal length settings, is an impressively short 0.5m (1.6ft). Curiously Nikon have opted for a 72mm filter thread that is at odds with many Nikkor lenses that generally have a 77mm, and on some models a 67mm thread.
A two-ring design that in common with some other recent consumer type Nikon zoom lenses has the focus-ring closest to the camera body. There is a paucity of information around the focus-ring - a distance scale that only has markings for infinity, 3m, 1.5m, and 0.5m, plus 15ft, 5ft, and 3ft. There is a total absence of any depth-of-field markings, and Nikon have not even bothered with an infrared index mark! Given that depth-of-field is different for the smaller DX-format sensor compared with a lens designed for 135-format 35mm film you would think that they could at least offer some indications, particularly at the short focal length end where it would be most useful.
Three switches located in a small panel close to the lens mount, on the left side of the lens (as viewed from behind the camera), complete the controls. The top switch selects either auto-focus with manual override, or manual focus only, the middle one is the On/Off switch for the Vibration Reduction (VR) function, and the lower switch is used to select the VR mode (Normal or Active).