Superzooms shouldn't be this good.
|
 |
For US$750, Nikon DSLR users get a do-it-all lens. Everyone wants to know if it's worth the money. Short answer: it is.
Here it is shown (left) next to the 18-70mm DX (right). |
| Lens
Formula |
16
elements in 12 groups; 3 aspheric, and 2 ED elements. |
| Other
Features |
Manual
focus override, AF-S lens focusing motor, vibration reduction, internal
focus,
72mm filter size. Comes with HB-35 hood. Focuses to
16.5" (0.5m). |
| Size
and Weight |
About
100mm long from mount (160mm extended), 1.26 pounds. |
| Price |
US$750 street |
|
The
Basics
One of the surprises with the D200 announcement was that it could be purchased with a new DX wide angle to telephoto zoom lens. Having a kit lens for consumer camera isn't new for Nikon, but this was a doozy: 18-200mm focal lengths plus vibration reduction and AF-S speed. This looked like the do-all, be-all lens for virtually everything except extreme wide angle, extreme telephoto, extreme macro, and extreme low light. In other words, a lens you would use most of the time. These all-in-one beasts have come to be referred by the trade a "superzooms," though most have proven to be far less than super.
The immediate question everyone asks is if a lens with such a range of features can be any good. I'll save you from scrolling down to the performance section: yes, beyond your expectations. But before we get to the details, we need to go over some...well...details.
First we have to discuss what DX means. All of the Nikon DSLRs (plus the Fujifilm DSLRs) have a sensor that's smaller than a 35mm frame. It's often referred to as APS size, as it's very close to the frame size of that now mostly forgotten film type. To wit, the 35mm frame is about 36mm across the long axis, while the Nikon DSLRs are all about 24mm across the long axis. That means that any 35mm Nikkor lens has an image circle that is far bigger than is necessary on the DSLRs. The DX series lenses are designed with an
image circle more appropriate to the smaller sensor size of the
digital lineup. Essentially, these lenses are designed solely
for use on Nikon DSLRs (and the Fujifilm DSLRs). The advantage of a DX lens is that it can be smaller and lighter than a lens of similar specifications that needs to cover the full 35mm frame.
As
I write this, we have seven DX lenses that have been announced:
the 17-55mm f/2.8G, the 10.5mm full
frame fisheye, the 12-24mm f/4G AF-S, the 18-70mm f/3.5-4.5G AF-S, the 18-55mm f/3.5-4.5G, the 55-200mm f/4-5.6G, and the superzoom that's the subject of this review. I expect we'll see additional DX lenses as time goes by.
The
first thing you notice about the 18-200mm DX lens is that it's rather small for what the specs say it can do. Where the heck is the 200mm and VR stuffed in? After all, this is a lens that's smaller and lighter than most previous mid-range zooms Nikon has made.
The
18-200mm focal range gives you angle of views from ~8 to 76 degrees
on a DSLR; it's effectively the same as using an 28-300mm lens
on a 35mm body. For some users, that's a stay-on-camera range. There's
no denying that this is a much-asked-for focal length
range. Indeed, even I find it interesting to walk around with this lens, the 10.5mm, plus a Canon 500D close up lens--that makes for a very compact, light kit that covers a pretty incredible focal length and focusing range. Still, I would have loved for it to be 16-180mm instead of 18-200--I miss that little bit extra at the wide end and rarely use the extra bit at the telephoto end.
This
is a two ring design; like most recent consumer Nikkors, the zoom ring is the front most ring and the focusing ring is closer to the camera. Yuck. The lens does have a distance scale, but
with no depth of field or
infrared
markings. For that matter, we only get three markings other than infinity for feet, and three in meters. You know, even if the lens manufacturers don't want
to give us complete depth of field markings, the least they could do
is mark
the hyperfocal point at one useful focal length and aperture combination and give us a few more markings.
In the case of the DX lenses, this is even more important, as
standard 35mm depth of field charts won't help you; you need
one designed specifically for the APS-sized sensors (copies of
which are in my DSLR books, by the way). On the left side of
the lens (from the back of the camera) three
buttons:
- Manual
Focus button: In the M/A position the lens
works as usual (autofocus with manual override). In the M
position, the lens focuses only manually.
- VR switch: VR can be turned On or Off.
- VR type: VR can be set to Normal or Active.
VR is specified by Nikon as being VR II--this new variant supposedly gives a bit more range to the VR usefulness. In Nikon's literature, they claim that VR II manages to get you four stops beyond what you'd normally be able to handhold. As far as I can tell, that's a valid claim at 200mm. But, be forewarned that VR is often much less useful than you might think. When you start hand holding a lens at 1/30 or lower, you're definitely going to be fighting subject motion. If your subject is absolutely static, fine, no problema as my South American friends like to say (sorry Brazil--I haven't been there to make friends yet ;~). But most of the folk that'll be using this lens aren't shooting completely static subjects with it, I think. The primary use for VR on this lens in my mind is to keep you from having to significantly boost ISO in common situations at 200mm (which would be f/5.6 maximum aperture). If the choice at that focal length were between shooting at f/5.6, 1/300, and ISO 1600 versus perhaps f/5.6, 1/60, and ISO 400 and I wasn't shooting a moving subject, I'd pick the latter just to keep noise under as much control as possible.
What VR (or VR II or even VR III when it appears) won't do is to allow you to shoot your daughter's night soccer game at 200mm and 1/15. That's a recipe for fuzzy players on sharp grass.
The
HB-35 hood supplied with the lens is the bayonet type butterfly
style. It can be reversed onto the lens for carrying, but it adds
significant diameter to lens when you do so. It's a bit shallow, so doesn't present a lot of shading for the front element from the sides, but it's far better than nothing, and it is more substantial than some of the butterfly hoods that have appeared for other Nikkor lenses. The lens itself uses 72mm filters, an odd size for Nikon and one that'll force almost everyone to buy a step-up ring of some sort (I use a 72-77mm step up, as my primary filter set is 77mm). For the consumer target of this lens, though, the filter size isn't a big deal, as this is likely to be their only lens, and thus they'll just buy 72mm filters.
You
get AF-S focusing with this lens, and that'll take you down to
a bit over 16 inches (.5m) at most focal lengths and a bit over 14 inches at 18mm. For those of you who keep track by magnification, that's about 1:15 at 18mm and about 1:4 at 200mm, both pretty good figures for a superzoom.
The supplied lens cap is the
pinch-front type.
Finally, one word about focal length. As with most zooms, focus point shifts the focal length a bit. At infinity, the lens is 18mm at its wide end, and I think a few millimeters short of 200mm at the tele end (I've seen one measurement that says 193.5; all I know is that it's a bit shy of my 70-200mm at infinity). At very close focusing distances, which is where I'm at most of the time, the lens is almost down to 17mm at the wide end, with very little perceptible change at the tele end. Perfect! Just the way I want it to be.
Other tests of this lens you might want to look up:
- Amateur Photography, 4 March 2006, p.39.
- Popular Photography, April 2006, p. 67.
- Bjorn Rosslett's mini-review.
Handling
Handling is not the strongest point of this lens, though good enough for the target audience. The zoom ring is stiff and has a very different feel at different focal lengths (I should note that some users claim it is loose and subject to zoom creep; that isn't the case on my sample). As you zoom in to 200mm, the zoom ring has a sudden "loose point" just before you get to the maximum focal length. Zooming the other direction is smoother, though still what I'd call rough. The barrel extends almost two-and-a-half inches (6cm) at 200mm, so you're moving a fair amount of plastic and glass during the zoom. The barrel doesn't rotate during zoom, which means that you don't need to readjust filters. The focus ring is better than the zoom ring, though it's thin and has nothing to distinguish it in feel from the zoom ring other than position and width. Remember, the focus ring is not in a "normal" spot, and this takes some getting used to if you're coming from the standard 35mm Nikkor lenses.
Focal length changes slightly when you're shooting at close distances. As with most modern "zoom" lenses, this is really a vari-focal lens, so you should be focusing after framing; I don't see this as a big deal.
Maximum aperture doesn't change the way you might expect with focal length. The relevant values are:
18mm f/3.5
24mm f/3.8
35mm f/4.2
50mm f/4.8
70mm f/5
135mm and higher f/5.6
The 18-200mm is pretty small and light for its range. It balances well on the front of a D200. I can see why the D200 and 18-200mm intros were simultaneous--they're a very good match for many users. On bigger cameras, such as the D2x, the 18-200mm is a little less balanced, but still okay. Either camera, I felt comfortable.
The switches are well located--as long as you can remember which is which--and can be easily moved from one position to another without looking away from the viewfinder. Still, I would have liked a bit more differentiation in feel so that I could tell by touch which is the focus on/off and which is the VR on/off switch (the VR type switch is smaller than the other two). Even something as simple as a round raised point versus an X raised point would have been welcomed.
Performance
I alluded to it earlier, so let's cut to the chase: on almost every performance parameter this is an excellent lens. Not perfect, but quite good at almost everything.
Sharpness
is excellent 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 sharp lens across virtually all of its range.) From 18-100mm my lens was everything you'd ever want in terms of sharp, so the way I look at it is that I've gotten a superb mid-range zoom that can give me a usable long telephoto in a pinch.
Vignetting (light falloff) was better controlled than I expected, considering the 18-200mm. At full aperture and 18mm, there's a good half stop of falloff in the corners, but by 24mm that's dropped to a third of a stop, and by 50mm a little less (it returns to a bit more than a third of a stop by 200mm, but at such telephoto extremes that's actually less light falloff than most shooters would desire). Two stops down from maximum aperture you'll never get more than a third of a stop of light falloff in the corners, an excellent performance.
Chromatic aberration is decently controlled, though not quite as good as the 17-55mm DX, especially at the wide end.
Images taken with the 18-200mm were sharp and contrasty, and in some situations, the VR also helped keep acuity high. I was a little worried that a superzoom design would show some inability to keep up with 10 and 12mp cameras, but that's simply not the case. Nikon is really showing that they can design excellent consumer zoom lenses lately. Indeed, of all the so-called superzooms I've used and tested, this is the first one that I'll keep.
Put the 18-200mm on an F6 and it becomes obvious why the lens has little light falloff at 18mm: the image circle isn't a circle! At this focal length the lens almost manages to cover the full 35mm frame; but it has a wavy pattern at the top and bottom of the frame that barely cuts off the corners. As you zoom past about 30mm the extension in the image circle disappears and you now have the traditional DX pattern of clipping the full frame corners significantly. This increases beyond 50mm so that the 200mm image circle is pretty tight to the APS sensor size. There's no point at which this lens covers the full 35mm frame.
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.
Autofocus
is fast and hunt-free. As I noted in my 17-55mm review, the primary focus speed difference between that lens and the 18-200mm comes in terms of the maximum aperture and in low light. In bright light, both are very sure and fast. In low light, especially at the telephoto end, the 18-200mm starts to lag, as it's just not letting as much light hit the autofocus sensors.
Flare
performance is quite good except for direct into the sun. Unless
light is hitting directly on the front element, I've not seen
any visible
contrast
degradation, and even then it's better than some Nikkors. Fortunately, the supplied butterfly type hood does a reasonable job of keeping light from hitting the front element in all but oblique side-lighting conditions. If the light source is directly in the picture, things get a
little wonkier, and you're likely to see contrast reduction if
not ghosting. That's typical of virtually all modern zooms, though.
I'm still evaluating bokeh, but my initial impressions are that the bokeh is acceptable, if not great (the lens features a 7-blade aperture diaphragm).
- Variable aperture.
The big issue is that at 200mm this is an f/5.6 lens, which means that autofocus in low light can be compromised slightly. Still, not a big issue, though a negative one.
- Complicated distortion. At the wide end, a bit of wave distortion is added to barrel; at most of the focal range, there's enough pincushion distortion to just be visible.
- Build quality. Build quality doesn't exceed the price point. I always worry about that slightly wobbly extension at 200mm--I'm not sure the lens would survive even a mild drop fully extended. And the zoom ring is rough on my sample (but apparently loose on some others).
- Super optics. Really, no significant flaws worth mentioning. Considering the price and the long focal range, superb performance.
- The 28-300mm for the digital world. Yes, the superzoom can be super. Considering the close focus ability, this lens really is going to suffice for 80%+ of the shots most folk take, at least if you don't need an f/2.8 or faster aperture.
- Price/Performance winner.
This is a far better lens than you'll ever expect, even for US$750. Far better. Good enough that it has replaced both my 18-70mm and 24-120mm as the walk around lens of choice for when I want to go light and with one lens.
|
performance