Introduction

For proper lens tests conducted in a laboratory setting or for professional field tests you should visit sites recommended in the Introduction and Links.  The commentary here is very informal and based purely on field experience. It is intended only as a quick reference to properties of lenses I am actually using. 

Nikon ("Nikkor") lenses come in professional ("pro") and consumer flavors. The pro series differs by having a more rugged construction (metal barrels and rings) and sealing against dust and moisture. They are usually a couple of stops faster as well which is important if you have to work in poor light without a flash. When it comes to optical quality it's difficult to compare because the focal lengths and ranges (for zooms) differ. In the consumer series Nikon uses more plastic in the mechanical structure and offers smaller maximum apertures but resolution and correction for aberrations seem every bit as good as what you get with a pro lens - and the cost is much lower. Occasionally a consumer unit might even outperform a pro (consider the 16 - 85 mm vs the 17 - 55 mm). Most of the pro lenses cover a full 35 mm size frame whereas a majority of the consumer series is APS-C (about 2/3 full-frame).

Reviewers will sometimes disparage the consumer series with remarks like "but it's not a pro lens" or "feels plastic-y". Professional photographers are often working to deadlines and don't have time to be careful or wait for the light to improve. They need durability and speed above all. All we amateurs really need is optical quality and the consumer series generally delivers the goods. We have the luxury of time to take care of our equipment and if the light is poor, we can usually come back tomorrow. So, don't get too worked up over the pro vs consumer arguments you might find. Both series feature excellent optics and you are likely to collect a few from each line.

Bear in mind there is no such thing as a perfect lens except, perhaps, in the astronomical world. Camera lenses must cope with finite, varying subject distances, variable aperture and - in the case of zooms - variable focal length. It is impossible to design a lens that will deliver perfection under these circumstances. Compromises are unavoidable.

In what follows the "DX" designation refers to Nikon's APS size sensors and "FX" to full format sensor sizes. Most DSLR camera bodies are "DX" (Canon uses another term but it is the same thing). A lens can be designed to properly cover DX only or both DX and FX, in which case it is simply "FX" designated (or not marked at all). More and more high-end bodies are coming out as "FX" but are very expensive. Both Rockwell and Hogan (see the Links section) go extensively into the DX vs FX differences and future developments.

Nikkor 18 - 200 mm VR (Consumer DX)

The first available "super-zoom" for a DSLR (DX format only). This lens has stirred up considerable controversy owing to the variety of experiences obtained at mid-telephoto. Give Nikon credit. This is the first industry attempt at a high ratio zoom for DSLRs and a lot of photographers (even pros) are delighted with the result. Canon has recently introduced a very similar offering. Early reviews suggest it is not nearly as good as the Nikkor but we will have to see more shots taken in the field to know for sure.

Ken Rockwell makes the astute observation that this unusual Nikkor (and by association the competing Canon) probably exhibits many "sweet or sour" focal lengths as all those pieces of glass move around in relation to each other when you zoom. This may explain the variety of experiences reported.

Plus:

• Unprecedented versatility with phenomenal zoom range.
• Very good wide-angle/normal and long telephoto resolution.
• Better than expected resistance to flare.
• When heavily stopped down (recommended in mid-telephoto range) diffraction is less of a problem than you would think.

Minus:

• Strong distortion at wide-angle. Fixable in software but a nuisance with architecture. You may never notice on landscapes.
• Bumpy mid-telephoto performance from about 120 mm to 160 mm with some distinctly soft zones. You can fix this by stopping down to F/11 or more but this restricts your control over depth of field and makes low light use challenging. Remarkably, diffraction does not seem to bother it very much at small apertures so you pick up more sharpness than you might expect.
• Very prone to zoom creep - a nuisance but some photographers actually like this, exploiting it as an alternative to using the zoom ring. It takes all types.

Both dpreview and photozone lab tests have documented the unevensss of mid-telephoto performance. Photozone remarks that it does much better "in the field". This is my experience as well, although you will want to avoid wide-open operation for best resolution. I suspect the lens redeems itself by having good flare performance, leading to high contrast, and a clean diffraction pattern when stopped down.

Conclusion:

If you are willing to manage the somewhat dodgy mid-telephoto range and can accept the limitations this imposes on use in subdued lighting you will probably be very happy. There's also the matter of wide-angle distortion which will make architectural shots problematic unless you don't mind fixing this in post-processing. Rather oddly, severe stopping down in mid-telephoto does not seem to incur much of a diffraction penalty so there's more good news. I have obtained phenomenally sharp images at F/19, right in the middle of that soft zone. The long telephoto end is fine if not exceptional.

Not a good choice for indoor sporting events because of that mid-telephoto range and how you must deal with it.

With those caveats in mind, a rational pick for the traveler who needs to go light but if you can pack two lenses, there are better choices (see Recommendations below).

If you shoot mainly for albums, computer/Internet or Hi-Def TV viewing you will probably never notice the mid-telephoto weakness even wide open. Your presentation intentions will determine level of satisfaction with this lens more than any other.

Could be an excellent portrait lens with the zoom providing full compositional control right where you need it. Furthermore, that focal length range (60 - 120 mm or so) is definitely the "sweet spot" for over-all performance (sharp, low distortion).

A somewhat ambivalent review - sorry, but that's how this lens is. Capable of fine results but you have to familiarize yourself with its peculiarities first.

Nikkor 16 - 85 mm VR (Consumer DX)

If I could have only one Nikkor, this might be the one. A real jewel. Photozone labs say this is simply the best DX Nikkor made for general use, surpassing even the "pro" 17 - 55 mm.

Plus:

• Very sharp at all focal lengths and apertures. You never have to think about helping it through a weak zone (unlike the 18 - 200 mm). Very little fall-off in resolution at the edges.
• Highly useful focal length range covering moderate wide-angle to portrait to short telephoto.
• Nice quasi-macro performance. Focuses to within a foot and stays sharp.
• Very good to excellent resistance to flare.
• Low distortion at wide-angle. Not quite an "architectural lens" but still good. Only minimal correction in software needed for extreme wide-angle shots.
• No zoom creep.

Minus:

• Nothing comes to mind apart from being a bit slow (F5.6) at the long end. This is not an image quality issue, however.

Conclusion:

The perfect "walk-around" and traveler's lens if you can do without long telephoto. It's sharp enough that the longest focal length images will withstand a great deal of cropping and/or enlargement, giving you more close-in or mid-tele capability than 85 mm would suggest. Close-up it can rival the 105 mm Micro Nikkor. Very forgiving, easy to use lens with its high flare resistance and no real weak spots.

Nikkor 70 - 300 mm VR (Consumer FX)

Excellent value and performance.

Plus:

• Extremely sharp from 70 mm to 250 and still good out to 300 mm.
• Useful as a long range quasi-macro because it focuses quite close.
• Full format coverage.
• Inexpensive (for a Nikkor).
• Light, easy to carry because of plastic rings and barrel.

Minus:

• At longest tele settings some chromatic aberration begins creeping in around the edges. This might be more of a problem on FX format(?). Easily fixed in software but a small flaw just the same. Rockwell reports no CA. Either he simply did not spot it or there is some unit-to-unit variation. In mine there is some but it is slight.
• Softens past 250 mm but still useful.

Conclusion:

Excellent portrait/wildlife lens, especially if you are on a budget. Never disappoints with that excellent resolution and no weak spots until about 250 mm.  Of course, 300 mm is still a bit short for wildlife and images soften past 250 mm even stopped down. The pro 70 - 200 mm Nikkor is doubtless a better lens but costs almost 4 times as much, is much heavier and requires an expensive tele-converter to obtain the same reach. If you can spare the cash probably a better choice in this focal length range although you might miss the extra 100mm.

I consider this an excellent 70 - 250 mm lens with the remaining 50 mm focal length useful but not exceptional.

Nikkor 12 - 24 mm DX (Pro DX but works on FX from 18 mm upwards)

Another winner. The poor man's 14 - 24 mm Nikkor. A pro lens for DX bodies.

Plus:

• Extremely sharp at all focal lengths and apertures. Sharp right out to the edges.
• Very good flare resistance (not as good as the 16 - 85 though).
• Pro series although plastic construction.
• Hogan claims it works well on FX bodies at 18mm and longer - a hidden bonus.

Minus:

• Some distortion at extreme wide-angle (nothing like the 18 - 200 mm).
• No VR but - you really don't need it at these short focal lengths. This is a nit.

Conclusion:

An excellent specialty lens for dramatic landscapes and other super-wide views. You can compose right out to the edges with confidence because resolution is so consistent. You will never see the moderate distortion at extreme wide except on architecture - easily fixed in software.

Nikkor 105 mm VR - "Micro Nikkor" (Pro FX)

A superb macro lens in the pro series.

Plus:

• Exquisitely sharp. Close-ups are dramatically detailed and vivid.
• Fast
• 105 mm focal length yields good/safe working distance when approaching wasps and snakes.
• The only stabilized macro on the planet (at time of writing) - a huge advantage in close-up work where camera shake can be so problematic.
• Pro lens. Rugged metal construction.

Minus:

• No performance issues but it is surprisingly large and heavy.
• Auto-focus can sometimes (rarely) hunt a bit close-up but this is easily managed by helping it out with the manual focus ring. The occasional problem results from the extreme focusing range sometimes yielding an image initially so blurred the focusing algorithms have nothing to work with. It is misleading to blame the lens in any event. AF is performed by the camera electronics. All the lens does is place a motor in the servo loop.
• A tiny bit of chromatic aberration at very large image sizes under some circumstances where specular reflections are present. Easily corrected in post-processing in the unlikely event it becomes visible.

Conclusion:

Possibly the ultimate macro lens if you are happy at this fixed focal length. There are other Micro Nikkors but none with VR. On DX format bodies the 105 mm is a bit awkward for general use. For indoor portrait work it's somewhat long and as a mid-telephoto it is less useful than the versatile 70 - 300 mm VR. But - if you are  a macro enthusiast who obsesses over image quality, this is for you. Hogan prefers the 200 mm macro for it's better working distance but - it isn't stabilized.

Sigma 150 - 500 mm

OK - not a Nikkor but a surprising performer (on a DX body, at least). I have provided a more detailed review and sample image gallery HERE so this is just a summary for convenience.

Plus:

• Sharp, often excellent over a DX frame, at most focal lengths and apertures - noticeably less so past 450 mm wide open but still good.
• Up-to-date HSM (hypersonic motor) delivers very fast auto-focus in conjunction with a good camera body such as the D7000/800
• Exceptionally effective optical stabilization (OS) makes hand-held use at 500 mm a realistic option but - it is somewhat slow to take control when first engaged.
• Appears well built ... smooth operation, no sag or wobble at full extension. Nice layout of controls, excellent removable/rotatable grip and tripod mount. A lot of thought went into this design.
• No chromatic aberration - quite remarkable.
• Superb carrying case with high density foam padding.

Minus:

• Quite slow (F/5, F/6) but that's how they make it affordable. Focusing speed/accuracy in low light and/or at long range can be compromised, requiring your attention..
• The OS takes 2 seconds at least to gain control of shake. Of possible consequence to sports photographers(?).  OS is noisy (whines, grunts and moans) but hard to imagine how this could be a problem to anyone.
• Large and heavy but how could it be otherwise?
• Zoom creep if held vertically or nearly so. A zoom-lock control would be nice but it's easy just hanging on to the front with your hand at extreme positions.
• Softens just a bit approaching 500mm but images still very good.
• Some reviewers report vignetting at certain focal lengths on full-frame bodies. I am not in a position to evaluate. Usually, vignetting can be corrected without penalty in post-processing.

Conclusion:

Good choice for the wildlife photographer on a budget, given the sharp, well corrected optics and excellent stabilization which minimizes need for a tripod. With practice you really can hand-hold at 500 mm and 1/100 s. The comparable  Nikkor would be the 200 - 400 mm at over 5 times the cost. I'm sure it is a better lens (it is certainly faster) but  the generally fine optical performance of the Sigma makes it entirely suitable for large images on glossy paper or on a hi-res monitor. Be sure to wait for the stabilization to kick in before taking a shot or you will get duds. I find it takes about 2 seconds.

Recommendations

Despite the popularity of the 18 - 200 mm VR as a "travel lite" lens the discerning DX format photographer who can afford to pack two lenses and who values image quality above all, under all circumstances, will be better served with the 16 - 85 mm VR and the 70 - 300 mm VR (or 70 - 200 mm if you have deep pockets). This combo covers practically all the bases from moderate wide-angle landscape to fairly long telephoto wildlife work without any performance concerns. These lenses (excepting the 70 - 200 mm) are compact and light besides.

From 18 mm to 85 mm the 18 - 200 mm is quite sharp so why not just get it and have the longer focal lengths available in a pinch even if they are a bit soft? The main reasons are distortion at wide-angle and resistance to flare in which categories the 16 - 85 mm is the clear winner and - it is still sharper throughout the overlap range.

The properties of other Nikkors reviewed pretty much speak for themselves. These are all excellent optics. The only lens in this line-up you really need to think about twice before purchasing is that 18 - 200 mm VR. If you fit the profile for presentation format (monitor/TV/album) and/or working environment (i.e., good light to help you through mid-tele with high F-stops) it could be the perfect fit. Otherwise, consider alternatives even if they are less convenient.

The Nikkor 80 - 400 mm does not appear here although it might seem a logical moderate cost (for Nikon) compact alternative to the Sigma. This Nikkor is an old design whose AF still relies on a motor in the camera body for operation and it's very slow to focus. This sort of lens would seem well suited for wildlife photography but for subjects such as birds, which move around a lot, I think you are going to get many duds. While the 70 - 300 mm VR does not have the reach, it is AF-S, focuses instantaneously and the number of successful shots is liable to be greater. Same applies to the Sigma. If Nikon ever gets around to modernizing the 80 - 400 mm it could prove a better choice than either of those lenses by providing an all-in-one option for the short to long telephoto range.

The Sigma 150 - 500 mm would seem a rational alternative to expensive Nikon glass if you need the reach, it's principle (and significant) drawback being a small maximum aperture. The main consequence of this is some impairment of auto-focus in subdued light and possibly at long range.