Friday, September 23, 2011

Nikon AF-S Nikkor 24-70mm F2.8G ED Review

The Nikon AF-S 24-70mm F2.8G ED was released back in 2007 along with the AF-S 14-24mm F2.8G, D3 and D300, and there are currently no signs of a replacement coming soon. I think it is safe to say that this lens will be an important tool for many Nikon shooters for years to come. There are plenty of reviews out there that cover the technical details of this lens, so I want to focus on the practical aspects of the lens for the most part. This review is based on my use of the Nikon 24-70mm F2.8G on a Nikon D700, so the comments and conclusions are based on use with that camera.

Without a doubt the first thing you will notice about the 24-70mm F2.8G is the size and weight. If carrying big, heavy gear around is not something you enjoy the 24-70mm F2.8G is not for you, because the lens is large and weights in at 900g (1.98 pounds). There are some very good reasons for the weight of the Nikon 24-70, first of all the dust and moisture resistant magnesium alloy shell around the glass. I think it is also safe to say that the glass itself is rather heavy.

Markings Indicate that there are Nano Coated, Extra Dispensation and Aspherical Elements.
Silent Wave Motor, with Internal Focusing. Accepts 77mm Filters.
When you consider the size of the 15 elements in 11 groups (3ED, 3 Aspherical and some nano coated) that cover the focal range of 24-70mm at the fixed aperture of F2.8, you have to figure that it will be heavy. If you are a full frame shooter who cannot handle that kind of weight, consider the lighter and smaller Sigma or Tamron options. Niether of those options are equal to the Nikkor in terms of optics or build quality, but they are viable alternatives.

The build quality of the Nikon 24-70mm F2.8G is outstanding, one of the best lenses that I have ever handled, comparable to the AF-S 70-200mm F2.8G VR and AF-S 300mm F4D IF-ED. The magnesium alloy body is tough, and dust a moisture seals help to prevent the ingress of water and dust. That does not mean the lens is waterproof, but it can handle light rain or snow without any trouble. As for how the lens feels in your hands, it is comfortable when mounted on a full frame Nikon DSLR like the D700 (with or without the MB-D10 battery grip). The combination of the D700 and 24-70mm F2.8G is well balanced, and despite the weight of the two, is very enjoyable to shoot with in practice. You will start to feel the weight after shooting with it for a few hours, but that is almost a given considering the weight.

What is the lens like to use in practice? In terms of operation, the lens is a pleasure to use, thanks to the fact that the zoom and manual focus rings turn smoothly. The zoom ring is responsive, and you wont find yourself moving from one position to the other so fast that you end up missing the focal range you want to use. At the same time it is not so stiff that you cannot zoom quickly in order to react to changing situations. The same cannot be said for the manual focusing ring though, which I consider to be a little on the loose side.  It is easy to achieve focus, but it is just as easy to focus past your subject, so you need to be very gentle when turning the ring. Of course, considering how fast and accurate the auto focus is with this lens, you'll be hard pressed to need to manual focus. As a side note, I find the manual focus ring a little too close to where you rest your hands on the lens when not operating the zoom ring. I think you'd have to handle the lens to get a feel for what I'm saying though.

What about focusing speed? The AF-S 24-70mm F2.8G features one of the fastest SWM (Silence Wave) focusing motors that I've used to date, matching, if not exceeding, the speed of the 70-200mm F2.8G VR. Of course, with blazing focusing speed some might question question how quiet the lens is when focusing, but in this case it is one of the quietest AF-S lenses in the Nikon len lineup. With some lenses focusing speed means that accuracy is compromised, but that does not seem to be the case with this lens. More times than not, the lens locks focus dead on the first time. The only times that I had problems with focusing were in extremely low light, or with erratically moving subjects. In the latter case it was more of my inability to keep up with the movement of the subject than any fault of the lens. There are a few occasions when you'll find the lens hunting for focus, but that is not a common problem.

I know your thinking, enough about the technical aspects, what about image quality? I believe that there is only one word can describe the image quality this lens provides, awesome! Of course with a price tage in the $1600 range (Cdn), the image quality had better be awesome. Although the overall quality of images comes down to the photographer, this lens can produce super contrasty and sharp results in the right hands. What about optical flaws? There is some vignetting and chromatic aberrations wide open across the zoom range (name a lens doesn't!), but once you stop it down to F4 those are a distant memory. The lens also suffers from barrel distortion at 24mm, and pincushion distortion at the long end, but neither of these characteristics are uncommon for a lens of this type.

What about the bokeh? I think the bokeh of the 24-70mm F2.8G is acceptable in most situations, although it looks best when you are closer to your subject. The 9 rounded aperture blades in the lens do there job to render the background out of focus smoothy. At 24mm you have to be within a few feet, due to the depth of field at the focal length to observe the quality of the bokeh. The samples below were taken a few feet away from the reeds. The samples display the quality of the bokeh, and show the effects of vignetting.

Samples at F2.8 (click on images for larger view)

What about flare? The 24-70mm F2.8G was one of the first Nikon lenses to have the Nano Crystal Coat applied to some of the elements in order to reduce flare and improve contrast in bright conditions. Does the Nano coat help in real life shooting though? I took some shots with the sun in the frame to find out. The shot below is a worst case scenario, so keep that in mind. The front element had some dust on it (I mention this because dust can/will introduce flare), which doesn't help matters any. Overall though, I think the amount of flaring isn't too bad for a zoom lens of this type. I've seen better performers in this area, such as the Nikon AF-S Micro Nikkor 60mm F2.8G, which showed no flare at all in similar tests. That being said, zooms are generally more prone to flare than primes, due to the number of elements in the lenses construction.

The Effects Of Flaring
Image Samples Taken With The 24-70mm F2.8G on The D700 
(Click Images For Larger View)

24mm F2.8
24mm F4
24mm F5.6
35mm F4
50mm F5.6
50mm F22
70mm F2.8
70mm F8
Conclusion and Comments:
The Nikon AF-S Nikkor 24-70mm F2.8G ED is a high quality, both in terms of image and build quality, zoom for full frame Nikon DSLRs. Of course this lens does have some short comings, like weight (900g), and some optical flaws as well, such as heavy barrel distortion at 24mm and chromatic aberrations wide open. If you spend all your time testing lenses, you'll quickly realize that they all have short comings, and that you're better off knowing what they are, and working with or around them. In the case of a high quality lens like the 24-70mm F2.8G, the flaws are far less prevalent than some others that I have used, so I don't get bogged down with them. From my perspective, these flaws or characteristics becomes non-issues when you get out and start shooting in real life.

What stands out to me about this lens is the optical quality (sharpness) and build quality. I feel confident shooting with this lens in wet or cold conditions, such as when I was shooting near a misty waterfall in the rain recently. My D700 and 24-70mm became wet all over, but neither stopped working in spite of this attack. Obviously if I was shooting in heavy rain I'd use a rain cover, but it can stand up against rain if you happen to get trapped in a situation where that isn't possible. 

  • Excellent Build Quality
  • Optically Very Good, Across The Entire Zoom Range
  • Produces Contrasty, Sharp Images even at F2.8
  • Fast and Accurate Auto Focus
  • Bokeh Performance is Good For This Type of Lens
  • Nano Crystal Coating Helps To Reduce Flare (but does not eliminate it)
  • Price ($1600 range) 
  • Weight (900g) Might Be Too Much For Some
  • Heavy Barrel Distortion at 24mm
Video Overview: