I’d never really considered getting a superzoom before. These things are notorious for having bad optics and nothing says ‘amateur’ more than having one of these mounted on your DSLR.
A couple of weeks ago, I borrowed a friend’s copy of the Nikkor 18-200 and did some casual tests. The Nikon 18-200mm VR is not the sharpest piece of glass out there. It was the least sharp out of the three zooms tested at the same focal lengths (tested: Nikkor 18-200, Nikkor 80-400, Sigma 50-150mm at 100mm f/5.6 and 150mm f/5.6). In addition, it has some other unpleasant characteristics: barrel/pincushion distortions, zoom creep, and some light fall off the extremes when shot wide open.
Why do I want one then? Well, for the following reasons:
While the 18-200mm is does not go wide enough for me to consider it as a ‘one lens’ solution, it is light enough that if I replace my Sigma 50-150mm, I’ll save about 200g (about a half pound). On a long trek or hike, like my upcoming Annapurna Circuit, that’s worth it. For this trek, I’ll also replace my normal wide-angle lens, the 12-24mm with the 10.5mm fisheye, saving me another half pound.
This is more than just the convenience of not having to change lenses. In travel photography, I don’t usually get to control my subjects or environment. My role is that of an observer and it means I have to work quickly to get shots as events unfold. There is usually no chance for a retake. Having the right lens on your camera at the right time could mean getting the shot or no shot. The Nikkor 18-200mm offers a wide range of focal lengths with acceptable quality*.
My D300 died on me during a trip down a river 2 weeks ago. It was protected in a Stormcase and it never got wet. There were 3 other SLRs on that trip, all Nikon: a D200, a D70 and a D40x. All of them were stored in soft drybags and they all survived the trip. Two were fitted with 18-200mm lenses and the older D70 was fitted with an 18-70mm lens. While the jury is still out on why my D300 failed, I suspect that reducing lens changes improves the camera’s weatherproofing, be it moisture or dust.
Pairs up well with the D300
With the low noise characteristics of the D300, I’m less afraid to bump up the ISO to accommodate the slow maximum aperture of the 18-200mm. Also, on my D300, the balance is perfect!
*Acceptable Quality: How good is this lens? I can put up with the lens’s other faults, but sharpness is important to me and I’m hoping that it will be sharp enough for a magazine double-page spread (11x22”).
Incidentally, from my lens testing, the Sigma was the sharpest, but required the large lens hood in place for best results. The Nikkor 18-200mm has surprisingly good contrast qualities, and in testing without hoods, it outperformed the Sigma in the contrast department. The moral of the story is: always use the lens hood.