Lens Sharpness and Contrast
Although Nikon released the 600mm f/4G ED VR at the time when a high-resolution DSLR did not yet exist, its superb optical design has been yielding very sharp images even on the most current DLSR cameras like the Nikon D6. So if you shoot with a DSLR that has up to 36 MP of resolution, you will be amazed by the sharpness of this lens. However, if you mount it on the latest high-resolution cameras like the Nikon D850 (45 MP), that’s when it starts to show its limits in terms of resolving power.
Take a look at how the lens performed in our lab with a 45 MP camera, as measured by Imatest:
As you can see, while the lens is certainly very sharp (especially at large apertures), a 45 MP sensor is certainly too much for the lens to handle. This is especially noticeable when comparing the lens to its successor, which you will be able to see on the next page of the review.
When it comes to colors and contrast, the lens certainly does not disappoint. You will see a drop in contrast when using teleconverters (especially 1.7x and 2x), but that’s expected, as explained below.
Nikon 600mm f/4G ED VR vs Nikon 600mm f/4E FL ED VR
Let’s now take a look at how the lens compares to its successor:
While the 600mm f/4G ED VR is no-slouch, we can see that the newer 600mm f/4E FL ED VR has much better overall sharpness, especially on a high-resolution camera. There is roughly a 10% difference in sharpness at large apertures between the two lenses, which is certainly quite a bit. Stopped down to f/8, there is very little difference though, even in the extreme corners.
Performance with Nikon TC-14E II and TC-14E III Teleconverters
While all Nikon super-telephoto lenses are designed to work with 1.4 teleconverters, their performance can vary greatly from lens to lens. Lenses like the Nikon 400mm f/2.8E FL ED VR are well-suited for all Nikon teleconverters, but the slower f/4 and f/5.6 lenses often do not fare nearly as well. I have written about variances in teleconverter performance in the Image Degradation with Teleconverters section of the linked article, which goes through all the factors that affect sharpness performance with different lenses and teleconverter combinations. Let’s take a look at how the Nikon 600mm f/4G ED VR performed with the TC-14E III. With the 1.4x magnification and a full stop of light loss, the lens essentially becomes an 840mm f/5.6 lens:
Although it isn’t great wide open, stopping down to f/8 results in fairly good sharpness. Add a boost of sharpness in post-processing software like Lightroom, and the results are quite usable. Unfortunately, the teleconverter seems to impact mid-frame and corners even more, so as long as you are not shooting flat subjects, it is a pretty decent combination.
Having previously used the Nikon TC-14E II with this lens, I did not notice drastic differences in sharpness or autofocus performance between the two versions. It looks like the lens performs very well with both.
Personally, aside from very specific subjects (such as the Moon, or when shooting distant subjects on a very clear and cool day without any atmospheric haze), I was never particularly happy with images from this combo. While you can get pretty decent results if you stop down a little, keep in mind that 840mm is a fairly extreme focal length and you really need to know what you are doing. A slight bump on the tripod or even the mechanical shutter can send a wave of shake to your camera. And if you have atmospheric haze, you will be looking at a very odd image that might only be partially sharp. Shooting at extremely long focal lengths is not easy, so keep this in mind.
Here is an image of a bald eagle, captured by John Lawson with the 600mm f/4G ED VR + TC-14E II:
Performance with the Nikon TC-17E II Teleconverter
Although I put the Nikon TC-17E II to test with this lens in the lab, I have never been happy with this combo, primarily due to autofocus accuracy issues. The Nikon 600mm f/4G ED VR hunts a lot with the 1.7x in less than ideal conditions, and the focus motor just feels too slow for shooting any action. The 1.7x teleconverter robs quite a bit more light compared to the 1.4x TC, making it a 1020mm f/6.7 lens. Let’s take a look at the sharpness results:
Yikes, not good. Using the 600mm f/4G ED VR with the 1.7x, is like stopping down to f/16 – the sharpness impact is too drastic. Although you can get a bit more sharpness by stopping down to f/8, it is still not sharp at the pixel level. The solution is to apply more sharpening in post, then down-sample the image (reducing image resolution) to get it to look reasonably sharp. Now if you shoot with a lower resolution camera body with less than 24 MP, images might look better, but if your hope is to shoot with a 45 MP sensor then crop the image to 100%, you will be disappointed.
Some photographers have better luck with the TC-17E II, but after trying it out a few times in the field, I just gave up.
Performance with the Nikon TC-20E III Teleconverter
The Nikon TC-20E III makes it a 1200mm f/8 lens, so you can imagine the consequences. I attempted to measure lens sharpness with the 2x TC in my lab, but every time the mid-frame came out sharper than the center, so I gave up trying. Autofocus was completely unreliable on the Nikon D810.
However, some very skilled photographers manage to capture images even with the 2x TC. Take a look at the below image, captured by John Lawson:
To capture this image, John used manual focus, since autofocus was unreliable. After some post-processing work and down-sampling, the image came out pretty decent!
One of the strengths of long telephoto lenses is the beautiful, creamy bokeh they are able to produce. At such long focal lengths, you are also dealing with background objects appearing much more out-of-focus and closer, allowing subjects to stay beautifully isolated from the background. The Nikon 600mm f/4G ED VR shines at this – it produces exceptionally good-looking background blur, whether you shoot wide open or stopped down, thanks to its 9-blade rounded diaphragm.
When it comes to vignetting performance, there is a little bit of light fall-off at maximum aperture when shooting at infinity, as can be seen from the chart below:
Imatest measured over 1 EV of light loss in the extreme corners at f/4, but stopping down to f/5.6 halves that, and if you stop the lens down even more, it basically disappears. Personally, I see no reason to shoot with a 600mm f/4 lens at infinity, so the only relevant numbers are at close focus range (which are more than acceptable).
If you are bothered by vignetting and you use software like Lightroom or Capture One, simply enable lens corrections, and the issues should be taken care of automatically.
Lateral chromatic aberration is reasonably under control at large apertures, as can be seen from the below chart:
You can also see the effect of teleconverters on lateral chromatic aberration – it increases only a little bit with the 1.4x, but much more with the 1.7x.
Ghosting and Flare
There is a reason why Nikon supplies such large hoods with its super-telephoto lenses – telephoto lenses generally do not do well with the sun or other bright objects reaching the front element of the lens. So, if you shoot against the sun, you might get some large, nasty flares and plenty of ghosting, which is quite normal. The integrated Nano and Super Integrated coatings certainly help in reducing ghosting and flare, but they do not eliminate it. So keep this in mind when shooting and avoid pointing your lens at the sun – you can actually get blind from doing this because everything is so magnified.
Distortion is usually not a problem on super-telephoto lenses. Imatest measured roughly 0.43% barrel distortion, which is something you would never notice in your images. Plus, I seriously doubt you would be shooting any straight lines with this lens. Distortion is generally not a problem, because it can be easily fixed in Photoshop or Lightroom using the Lens Correction module.
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