Nikon 18-200mm f/3.5-5.6G

       The Nikon 18-200mm f/3.5-5.6G IF-ED AF-S VR DX Nikkon was introduced in November 2005, and rapidly became a much sought-after lens for the Nikon shooter's armoury. With its hugely useful 11.1x focal length range, 'silent wave' focusing, and Nikon's second generation vibration reduction system to combat camera shake, this lens aims to be the ultimate single-lens 'walkaround' solution, which photographers who wish to travel light can simply leave on the camera all the time.

       Of course the all-in-one 'superzoom' concept isn't new; the first such lens was Tokina's 35-200mm from 1982, but early designs were plagued by excessive size and weight, poor optical quality, and unacceptably long minimum focus distances. Indeed it wasn't until the mid-1990s that the likes of Sigma and Tamron introduced truly practical superzooms which substantially overcame these issues, and delivered acceptable quality across the range (for the casual vacation photographer at least). Since then, the rapid progress of computer-aided lens design has resulted in continued improvements in optical quality and extensions in zoom ranges, whilst shrinking lens sizes still further, making the superzoom concept more tempting than ever before.

       Sharpness is very good throughout most of the range, with f/11 being the point of maximum sharpness on my sample once you get to 100mm. At the wide angle end, though, there's actually little to distinguish the central area in one aperture from another--go ahead and use maximum aperture if you'd like. At all apertures at 200mm you'll see a bit of softness, with the best apertures being f/11 through f/16. (I should note that I've seen tests from others that say the opposite--that their sample was a tiny bit soft, especially in the corners at 18mm but pretty darned sharp across the board at 200mm. Sample variations do abound at the lower price points. But the conclusions are usually the same: this is a decently sharp lens across virtually all of its range.) From 18-100mm my lens was everything most people would ever want in terms of sharp on the 6mp to 12mp DX DSLRs, so the way I look at it is that you get a decent mid-range zoom that can give you a usable long telephoto in a pinch.

      Distortion performance is good. At both ends there's measurable distortion (about 1 percent complicated barrel at the wide end, slightly less than 0.5% simple pincushion at the telephoto extreme). Curiously, the best distortion performance is somewhere around 20mm (above that and we start getting pincushion, below that and you have barrel). By complicated barrel I mean that there's just a bit of mustache, or wave, distortion in the barreled lines. Simple tools won't correct it fully. This isn't an architectural lens, but it's far from a fun-house lens.

       Flare performance is quite good except for direct into the sun.

       Autofocus is fast and hunt-free.

Specifications
Street price	• US: $680
Date introduced	Nov-05
Maximum format size	DX
Focal length	18-200mm
35mm equivalent focal length(APS-C)	27-300mm
Diagonal Angle of view (APS-C)	78º - 8º
Maximum aperture	F3.5-5.6
Minimum aperture	F22-36
Lens Construction	• 16 elements/12 groups • 2 ED glass elements, 3 aspherical elements
Number of diaphragm blades	7, rounded
Minimum focus	0.5m
Maximum magnification	not specified
AF motor type	• Compact silent-wave motor • M/A mode for rapid switching between Auto and Manual focus
Focus method	Internal
Image stabilization	• VR II, 4 stops • Auto panning detection • 'Active mode' for shooting from moving vehicles (no panning)
Filter thread	• 72mm • Does not rotate on focus
Supplied accessories	• Front and rear caps • Lens Hood HB-35• Soft Case CL-1018
Optional accessories	72mm filters
Weight	560 g (19.8 oz)
Dimensions	77 mm diameter x 96.5 mm length (3.0 x 3.8 in)
Lens Mount	Nikon F only
Other	Distance information output to camera body

Major features of the Nikon 18-200mm f3.5-5.6G IF-ED AF-S DX VR Zoom-Nikkor lens:

• Offers a broad 18-200mm focal range (11.1x zoom) for use in a variety of situations (equivalent to a 27-300 mm lens in 35mm format); VR II Vibration Reduction system offers the practical equivalent of using a shutter speed 4 stops faster 
• Two ED glass and three complex aspherical lens elements minimize chromatic aberration, astigmatism, and other forms of distortion while ensuring high resolution and contrast 
• Incorporates a compact SWM (Silent Wave Motor) for quiet focusing. Delivers high-level optical performance that is specially designed for use with the Nikon digital SLRs 
• Employs a seven-blade, rounded diaphragm opening that achieves a natural blur for out-of-focus elements 
• Enables focusing from as close as 50 centimeters (20 inches) from the subject through its entire focal range 
• M/A mode for rapid switching between autofocus and manual focus operation 
• Internal Focusing (IF) design simplifies the use of circular polarizing filters
• Nikon Super Integrated Coating (SIC) offers superb color reproduction while minimizing ghosting and flare 
• Flower-shaped lens hood HB-35 (included) greatly reduces stray light, enhancing image quality