Friday, May 13, 2011

Nikon AF Nikkor 20-35mm F2.8D Review (FX)

Nikon AF Nikkor 20-35mm F2.8D IF

Introduction:
The Nikon 20-35mm F2.8D was the first wide angle zoom made by Nikon, upon it's release in late 1993. In 1999 Nikon replaced it with the AF-S Nikkor 17-35mm F2.8D, although production of the older 20-35mm F2.8D did not stop until 2001. Unlike Nikon's modern wide angle zooms the 20-35mm F2.8D is rather compact in terms of size. The lens features a fast aperture of F2.8 throughout the zoom range and accepts 77mm filters, like most other pro Nikon lenses. The 20-35mm F2.8 is a D lens, which means that it sends distance information to the camera, and supports matrix metering on all modern Nikon digital and film SLRs. The lens can meter with all modern Nikon cameras, but it will not auto focus on cameras like the D40, D60, D3100 or D5100.

The lens originally shipped with a front 77mm Nikon cap (not modern pinch style), standard rear cap and the Nikon HB-8 Hood.


Build and Mechanical Quality:
The Nikon 20-35mm F2.8D is made of metal, with a crinkle finish on the surface of the outer barrel. This finish makes the lens very comfortable to hold in practice. There are only two piece of plastic on the lens, the first being the cover over the focus scale and the other being the AF/M switch that allows you to switch from auto focus to manual focus without moving the AF/M switch on the camera body. The manual focus ring is covered with rubber and operates smoothly and is well dampened, which is good because the range of manual focus is rather short. 

The zoom ring is similarly covered in rubber and is very smooth in operation, just like modern pro zoom lenses, such as the Nikon 24-70mm F2.8G. The front element of the lens does shift while zooming, but not very much. At 20mm the lens is fully extended, and the inner barrel slightly moves inward as you zoom towards the 35mm end of the range.

The build quality of the lens is pro grade, but being of an older design it does not have any dust or moister seal.


Auto Focus, Speed and Accuracy:
Focus on the 20-35mm F2.8D is driven by an in camera focusing motor, which all current Nikon FX bodies have. The lens has an internally focusing design, so it does not extend or rotate when focusing. On the Nikon D700 the lens focuses from 50cm to infinity in about 1 second. Auto focus accuracy seems to be dead on with my copy, with no noticeable focusing errors taking place wide open at F2.8.

The M/A switch on the 20-35mm F2.8D works differently from the ones found on modern AF-S lenses. When the switch is set to A (auto focus) the manual focus ring locks and does not move. This is nice, because you know that you wont be damaging the cameras focus motor if you accidentally grab and attempt to turn the manual focus ring. If you press the small button on the switch and turn it to M (Manual) position the ring will be unlocked and you can manually focus the lens.


Image Quality:
From my testing and field use of the 20-35mm F2.8D, I find it to be a remarkably sharp lens, at least once it has been stopped down. Wide open the lens is sharp in the center, but the edges are on the soft side. The best edge to edge sharpness is found between F8 and F16, making this a great lens for landscape photography. At F22 diffraction becomes an issue and some sharpness is lost. Resolution figures from this lens may not match the 14-24mm F2.8G, 17-35mm F2.8D or 16-35mm F4, but considering the age of the design it does very well.

During the course of usage I haven't noticed any significant optical flaws, although like most fast lenses it shows some CA (chromatic aberrations) wide open. Under some conditions, flare can be an issue, but usually removing filters eliminates the problem. You will also notice some barrel distortion at the 20mm end of the zoom range, which is gone by the time you reach the 24mm position. The barrel distortion itself is very minor in nature compared to the newer wide angle Nikkors. The lens produces contrasty images with rich colour, which as mentioned before, makes it well suited to landscape photography.   

Image Samples:
I have generally used this lens for landscape photography, so these samples reflect that. As a result the samples show the lenses performance stopped down more than anything else. All images take with the 20-35mm F2.8D mounted on a Nikon D700. Click on the images for a higher resolution image.

20mm @F16

20mm @F16

24mm @F4

28mm @F16

35mm @F16

35mm @F2.8

35mm @F4 (Vignetting Added To This Image)

Comments and Conclusion:
The Nikon AF 20-35mm F2.8D may be a older lens, but you can quickly see why this lens was in many pro photographers bags during the 1990s. The built quality of the lens is excellent, auto focus speed is very fast, colour rendition is natural and images are contrasty. The lens shows boarder softness wide open, but sharpness is good at F4, very good at F8 to F16. Stopped down the lens is very sharp, and due to the modest barrel distortion for a wide angle zoom, makes it great for landscape photography. The only real limiting factors are that it doesn't focus as close, or go as wide as modern wide angle lenses.


Pros:
* Sharp from corner to corner when stopped down
* Small and light compared to modern wide angle Nikkor lenses (14-24 F2.8G, 16-35mm F4G)
* Pleasing colour rendition
* Modest barrel distortion for a wide angle lens
* Excellent build quality (Pro grade, but not moisture/dust sealed)
* Used prices are half that of modern pro wide angle lenses ($700-800)

Cons:
* Doesn't focus as close as modern wide angle Nikkor lenses (0.5m minimum)
* Only sharp in the center at F2.8 (normal for wide angle Nikkors from that era)
* Not as wide as modern wide angle Nikkor lenses (14-24mm F2.8, 17-35mm F2.8, 16-35mm F4)
* Older lens, but still not inexpensive

Video Overview