Lens Sharpness and Contrast
I spent a considerable amount of time testing the Nikon 70-200mm f/2.8E FL VR in the lab. Unfortunately, the two lens samples I tested had all kinds of problems – from pretty severe focus accuracy issues I pointed out earlier and decentering issues, all the way to very noticeable focus shift that made it tough to properly test them. Focus shift seems to be a problem with the overall design of the lens – both lenses exhibited it at all focal lengths. As a result, I had to focus the lens for each aperture separately, which when combined with measuring sharpness at 1mm intervals on a macro rail took quite a bit of effort to complete. Unfortunately, focus shift is a pretty big problem on DSLRs, because lenses focus at their widest aperture when using phase detection autofocus, so if you are stopping down to a smaller aperture, you might see a visible shift in focus.
Despite these troubles, the first sample I tested was better optically than the second one (which had a pretty badly decentered lens element, resulting in poor sharpness results at the edges of the frame). Let’s take a look at the numbers obtained from Imatest at different focal lengths using the first lens sample:
Now keep in mind that the numbers presented here are the best case scenarios, where I took the best results from focusing at different apertures and distances using a macro rail. As you can see from the first chart measured at 70mm, the new Nikon 70-200mm f/2.8E FL VR shows superb performance wide open and once stopped down to f/5.6, it is a very sharp lens, even at the edges of the frame.
The lens continues to deliver superb results at 85mm and 105mm focal lengths, showing stellar sharpness at the maximum aperture of f/2.8, although the corners experienced a noticeable drop at 105mm. Due to the field curvature of the lens, slightly defocusing the center of the frame resulted in much improved corner performance.
And at 135mm, the lens reaches its peak performance, showing incredible sharpness that is better than most other Nikon lenses stopped down:
Unfortunately, there is a visible drop in sharpness at 200mm (more testing is required at this focal length with another sample), which is expected from a 70-200mm lens design. We can see reduced performance at maximum aperture, but once stopped down to f/4 and smaller, sharpness levels come back again:
Note the higher level of sharpness at the edges of the frame when zoomed in.
As you will see from the lens comparisons section below, the new Nikon 70-200mm f/2.8E FL VR is noticeably better in terms of sharpness compared to its predecessor, which is a huge achievement. The new optical design is clearly superior to what Nikon has done in the past, resulting in perhaps the best 70-200mm lens on the market today. While the sample variance and focus shift issues I described earlier are indeed alarming, it is important to point out that previous generation 70-200mm f/2.8 lenses were not free from such issues either. That is why I always recommend to thoroughly test lenses when committing to a purchase. Still, I am planning to test yet another sample of the 70-200mm f/2.8E FL VR to see how it would behave compared to others, especially in the lab environment. I will update this section with new results as soon as possible.
When it comes to color and contrast, the new Nikon 70-200mm f/2.8E FL VR performed similarly to its predecessor, which is superb.
Lens Construction
If you are wondering about the optical formula of the lens, take a look at the below illustration:
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