The Nikon 18-70mm f/3.5-4.5 G ED-IF AF-S DX lives up to all of its letters.

Introduction

A "kit" in the camera world is a camera body and a lens (usually a zoom). Any pro photographer knows to stay away from kits. Why? Because the vast majority of lenses included with kits are sub-par performers. In the 1990's, a lot of kits from the top camera manufacturers consisted of a mid-level SLR and a piece of garbage lens that was an insult to the camera body (and often the photographer). I figured this is the way it would always be so I just pledged to never buy a kit. Nikon has changed the rules with the Nikon 18-70mm f3.5-4.5. This lens came with my friend's Nikon D70 and right away I could tell that this was not your ordinary camera kit. Still, I wasn't convinced so I spent a lot of time using this lens to shoot some indoor events with a lot of people, as well as general outdoor scenics. So far, I've been impressed.

Features

According to the manufacturer:

- Compact 3.8X zoom covers portrait to wide view (76 degrees at 18mm to 22 degrees 50 minutes at 70mm).

- Optimized DX lens design is compatible with every Nikon D-Series digital SLR cameras.

- Three Nikon ED glass elements, plus one aspherical element for low distortion and minimized chromatic aberration.

- Exclusive Silent Wave Motor for high-speed auto-focusing with accuracy and super-quiet operation.

- Internal Focusing (IF) for smoother operation and great balance.

- M/A mode for instant switching from auto-focus to manual Nikon D-Signal technology for enhanced flash and ambient exposure control.

Specifications

- Focal Length: 18-70mm
- Maximum aperture: f/3.5
- Lens construction: 15 elements in 13 groups (three ED glass lens elements, one aspherical lens element)
- Picture angle: 76 degrees- 22 degrees 50 minutes
- Minimum focus range: 0.38m (15 in.)
- Max. reproduction ratio: 1:6.2 (.16)
- Filter Size: 67mm
- Dimensions (Diameter x Length): 073 x 75.5mm (2.9 x 3.0 in.)
- Weight : Approx. 390g (14.8 oz.)
- Case: CL-0915 Soft Case
- Included accessories: HB-32 Hood, CL-0915 Case, 67mm lens cap, rear cap

This lens has a polycarbonate outer body and a metal lens mount.

Performance

Ergonomics

This very compact lens is surprisingly not too compact ergonomically; it is just long enough to fit comfortably in my above average size hands, which is important for camera handling and control. Both the zoom ring and manual focus ring are easy to grip and turn. The zoom ring is wider than the manual focus ring and is nicely coated with a rubber grip. The manual focus ring has plastic ridges which aren't quite as comfortable or easy to grip, but still not bad. The manual focus / manual focus and auto focus switch on the side requires some commitment to move. This could be a good thing because it helps prevent accidental changes to the type of focusing. This lens is relatively light weight, with most of the weight located near the front of the lens. On the Nikon D70, it balances well without being too heavy to throw in a hip back for a day hike. Finally, the focus distance window on the top of the lens is sufficiently large for good visibility, except in low light conditions.

The included lens hood (thank you, Nikon) works well to reduce lens flare and add some protection from the elements, but it doesn't mount on and off as nicely as the higher end Nikkor lens hoods. There is very little friction as I screw it on, and then it clicks firmly into place at the end, perhaps a little too firmly. Sometimes I feel like I'm putting a lot of torque on the lens when I take the hood on or off. At least it's never going to fall off when properly mounted. It can be reverse mounted for storage, but it covers the zoom ring in this position so it needs to be removed or mounted normally to use the lens.

The included lens cap is the newer center-pinch design from Nikon (thank you again, Nikon), which is my favorite type of cap from any manufacturer. Very easy to use in all conditions and very durable. The rear cap is the standard issue, no frills design that still works well.

The aperture ring...oops - there is no aperture ring! Nikon's G-series lenses require electronic (in-camera) control of the aperture. This renders this lens useless on all manual focus Nikon bodies, such as the FM3A and FM10. Although I understand the reasoning behind this transition to all camera controlled apertures, I don't like it simply because of the loss of compatibility. Nikon has stated that they are committed to continuing the production of manual focus bodies - hopefully the same will be true of manual aperture lenses.

Mechanical Performance

Zoom ring dampening could be much better. I really have to try to achieve smooth movement of this ring. The first movement is usually very jerky but if I maintain the momentum, I can continue the movement in a somewhat smooth manner. This leaves a bit to be desired, and is probably something that keeps down the cost of this lens down. A 90 degree rotation of my hand zooms the entire range of this lens, from 18mm to 70mm. When fully zoomed to 70mm, the front of the lens extends approximately 1.1 inches beyond its fully compacted length at 18mm. The two section design of the extension does a nice job of limiting the total amount of extension and seems to be the design of choice in this zoom range for a mid-level lens from both Nikon and Canon. I haven't had any problems with dust being sucked into the lens during zooming, yet.

The manual focus ring is much smoother. However, it obviously lacks the superb dampening of something like the Nikkor 135mm AIS. If you need smooth, precise manual focusing capability, this lens is probably not for you. At least try it in a store first to see if it is suitable for your needs. Despite some shortcomings in the dampening department, the manual focus ring does one thing very well - full-time manual focus override, even when the lens is in autofocus mode. Every mid-level and pro-level lens should have this feature. Leaving the focusing selector switch in the M/A position means you always have the best of both worlds: high-speed AF-S autofocus and full-time manual override. Finally, focusing is internal which means no movement of the front lens element. This is a big bonus to photographers who frequently employ the use of filters.

Focusing in autofocus mode is fast, thanks to the AF-S system. Although not quite as fast as the AF-S on my Nikon 300mm f4, it does not disappoint. This system uses ultrasonic wave energy to drive the focus process, which significantly increases focusing speed while almost completely eliminating focus motor noise. I've found Nikon's AF-S to be very comparable to Canon's superb USM II focusing system.

After thousands of shots, this lens continues to perform flawlessly in terms of its mechanical operation. I have yet to have a single problem with zooming or focusing. In many ways, this lens reminds me of my old Canon 28-105mm USM lens, except that the tolerances seem tighter in this Nikon.

Optical Performance

At all apertures and focal lengths, this lens exhibits much above average sharpness when compared to similar zoom lenses in its price range. Not quite up to the sharpness standards set by Nikon's professional lenses, but it's almost there and this lens costs several times less. Besides some minor barrel distortion at 18mm, this lens has only one significant image quality problem, which is vignetting. While moderate apertures control vignetting fairly well, f/3.5 produces noticeable vignetting, especially at the widest angles and against uniform backgrounds (i.e. blue sky). When I first considered using this lens as my primary walk-around lens, I concluded that the amount of vignetting was too much. However, this is the easiest image quality problem to correct with almost any modern photo editing software, so I no longer worry about it. Color rendition is very good, although not as good as Nikon's professional lenses. Similarly, contrast is very good, but again not quite as good as the pro-level lenses, especially at large apertures. Chromatic aberration is very well controlled and almost never visible, even on close inspection. Overall, the optical properties of this compact zoom lens are surprisingly, and refreshingly, very good.

UPDATE: December 22, 2007. To read more about just how good this lens can be, read my comparison to its big brother, the Nikon 17-55mm AF-S f/2.8.

Conclusions

Not to be mistaken for the common "kit" zoom lens, this fine zoom from Nikon will likely impress any photography from beginner to advanced amateur, especially considering its more than reasonable price. Optical quality is very good, focus is fast, and the maximum aperture is large enough for most situations. Although it is not built to professional standards, Nikon has a winning zoom lens here that I can easily recommend to everyone else.