a super zoom worth owning?

Purists would balk at the idea of a single zoom that covered all the usual focal lengths from wide angle to telephoto. Its been tried many times in the past, often with disastrous results. There is good reason why most top-shelf zoom lenses cover a very small zoom range. The more you try to make the lens do, the worse it does it. Prior to the digital age I would not have recommended anyone even consider such a lens because the reality is that there is almost always significant distortion at all focal lengths with this kind of a lens. Now in the age of Photoshop it is trivial to correct these problems and considering that the 18-200mm Nikkor has no optical flaws other than distortion, this purchase seems like a sound decision to most photographers. Before I get to far ahead of myself.... lets look at the specs from the Nikon site.

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Focal Length: 18 -200mm (equivalent to a 27-300mm lens in 35mm format)

Maximum aperture: f/3.5 - 5.6

Minimum aperture: f/22 - 36

Lens construction: 16 elements in 12 groups (two ED glass elements, three aspherical lens elements)

Picture angle: 76 degrees - 8 degrees

Minimum focus range: 0.5m (1.6 ft.)

Attachment size: 72mm

Dimensions (approx.): 77 x 96.5mm (3.0 x 3.8 in.)

Included accessories: LC-72 72mm snap-on front lens cap; LF-1 rear lens cap; HB-35 bayonet hood; CL-1018 flexible lens pouch

Weight (approx.): 560g (19.8 oz.)

Optional accessories: 72mm screw-in filters

MSRP is about $699 but can vary since the lens is in high demand right now.

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Wow.... that’s a lot of lens. Let's break down some of the terminology that you find in the lens model name.

Nikon AF-S Nikkor 18 - 200 mm f/3.5-5.6G DX ED VR

AF-S means that you can safely manually focus the lens while in AF mode. You just grab the ring and adjust. No need to worry about damaging your camera. The focus motor is in the lens, not the camera.

18-200mm is equivalent to 27-300mm in 35mm terms. That’s a LOT of reach in such a small package.

F/3.5-5.6: the lens has a variable aperture (it changes as you adjust the focal length. A fixed aperture lens would be considerably larger, heavier and more expensive.

G: The lens does not have a manual aperture ring and can only operate correctly on Nikon cameras that have electronic aperture settings. That means it won't work on a manual focus camera like an FM3a or FM10

DX: the lens is designed to cover an APS-C sensor and will not fill a standard 35mm frame. As a result it is only fully functional on a Nikon digital camera.

ED: A special type of low dispersion glass that is meant to correct color aberrations and reduce flaring.

VR: The lens uses a vibration reduction technology that allows the lens to be used at slower than normal shutter speeds without blur. The manufacturer claims a 4-stop improvement. Typically a lens should be operated hand held only at shutter speeds faster than the reciprocal of the focal length...so at 70mm you should only hand-hold the camera at shutter speeds of 1/70th of a second or faster. With the VR technology you should be able to handhold the camera with 4 less stops of light or about 1/4 sec. That's a major improvement!

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Construction:

Construction is largely plastic with metal innards. Its that black polycarbonate that most of Nikon's sub-pro lenses are made from. It is average in construction quality and about what you would expect for a lens that costs only $700 but does so much optically. There is some slop in the zoom and focus rings and I wouldn't be taking bets that it would survive a fall onto concrete....but its built well enough that it will hold up to many years of moderate-severe use. It is not designed with professional use in mind. There are no weather seals on the lens.

Once again Nikon has felt the need to place the focus ring in the REAR...behind the zoom ring. The zoom ring is large and easy to manipulate but the focus ring is an afterthought and poorly placed. The lens includes a scalloped lens hood and a drawstring pouch for storage. The lens uses 72mm filters. I truly wish that Nikon had seen fit to use 77mm filters as this is pretty much the standard in pro-optics. Using a lens hood with a filter AND a step-up rings is not an easy thing.

Optical Performance: Here is the good news. The lens is sharp even at moderately wide apertures. It shows no color aberrations that I could detect. It's got great range from VERY wide to a nice moderate telephoto (300mm in 35mm terms)

Here is the bad news. The lens shows distortion at pretty much all focal lengths. It's pretty severe barrel distortion at the 18mm range and some pretty visible pincushion distortion at even moderate focal lengths and higher. It is all very correctable in Photoshop and I daresay that most armature photographers would hardly even notice it. There is good reason that top-shelf zooms cost so much.... distortion and construction quality are MUCH improved. You do get what you pay for. Now a pro who shoots 2000 images a week is not going to want to correct each and every images (even just his/her KEEPERS) for distortion to make them perfect. The hobbyist has more free time for such things and will do quite well with this lens. Most photographers will not consider the distortion worth correction except at the 18mm setting.

The VR works quite well but I do wonder about the 4-stop claim. I was able to take some nice 50-70mm shots in the 1/8-second range but they were not perfectly sharp. VR is a nice thing.... but it’s not a magic cure for low light and long shutter speeds.

Conclusion: I wouldn't want to make my living with only this lens as it introduces a little more work into the digital workflow. But If I was going on a vacation and wanted to keep things simple, then this lens would be the obvious choice. I bought one for exactly this kind of situation.... lots of lens range in a small package for when I don't feel like carrying around 3 other lenses to cover the same focal length. For most hobbyists and even prosumers this lens might be the ONLY one they ever need.


Think of it as the Nikon 18-70mm kit lens that comes with the D70....except it has a lot longer reach. Same optical characteristics, great value.