Nikon Z 800mm f/6.3 VR S Focus Speed and Performance
The Nikon Z 800mm f/6.3 autofocuses surprisingly fast. This was not a given considering that it’s an f/6.3 lens, but even on my old Nikon Z7, I was able to get plenty of photos of birds in flight with this lens. The accuracy is also excellent, even a bit better than an F-mount lens with the FTZ adapter.
Because of the narrow maximum aperture, the Nikon Z 800mm f/6.3 runs into some troubles autofocusing in very low light conditions. However, I didn’t find this to be a problem until I needed to raise my ISO to at least 12,800. This photo was taken with autofocus well after sunset, and it’s properly focused on the coyote’s eye:
That said, this is one of only a few sharp results among several out-of-focus photos I took of this coyote. If you take a lot of wildlife photos before sunrise or after sunset, you’d be better off with a 400mm f/2.8 lens or similar.
The close-focusing capabilities of the Nikon Z 800mm f/6.3 VR S aren’t great, but it’s good enough to photograph most small birds without an issue. For the tiniest hummingbirds, however – or other small subjects like dragonflies and lizards – you may want to pick a different lens.
The Nikon Z 800mm f/6.3 VR S has a low level of pincushion distortion, just 1.19% according to my lab tests. This is unlikely to matter to most users of this lens, who probably are not using it for architectural photography. But never say never – I could imagine some really interesting and unique cityscapes taken at 800mm, for example. Either way, the low level of distortion is certainly better than the alternative.
Here’s a simulated chart of 1.19% pincushion distortion for context:
In uncorrected images, the Nikon Z 800mm f/6.3 VR S has very low levels of vignetting wide open, though it depends on your focusing distance. It’s worst at f/6.3 and infinity focus. Here’s a full chart of vignetting levels:
Considering that anything less than one stop of vignetting is basically negligible in real-world photos, this is an excellent performance. You will rarely see any vignetting with the Nikon Z 800mm f/6.3 VR S even when shooting wide open against a flat sky.
That said, if you’re an Adobe Lightroom user, keep in mind that Lightroom’s lens profile directly reads information from your in-camera vignetting reduction setting. If you want your photos from this lens to have full corrections by default in Lightroom, you need to turn the vignetting correction to “High” in-camera. This is true even if you’re shooting .NEF files. It’s not a big deal because you can always add or remove vignetting manually, but I recommend turning the in-camera corrections to “Medium” or “High” to minimize your post-production work, even with the low levels of vignetting on the Nikon Z 800mm f/6.3 VR S.
There is very little chromatic aberration on the Nikon Z 800mm f/6.3 VR S no matter what aperture you use. Here’s the chart:
Anything under about one pixel is almost impossible to notice in real-world images, even with chromatic aberration corrections turned off. This amount is low enough to be totally irrelevant. Likewise, I noticed very little longitudinal chromatic aberration on the Nikon Z 800mm f/6.3 VR S (where out-of-focus areas shift color). Nikon did a great job here.
I’ll start this section with some real-world crops to show the sharpness of the Nikon Z 800mm f/6.3 VR S in practice. Hopefully that helps you contextualize the lab results that I’ll show in a moment.
First, a basic example at f/6.3 with the subject directly in the center of the frame:
Then a 100% crop. (All of the 100% crops I’m showing in this section are about 2000 pixels wide / 2.6 megapixels to make things consistent. They’re excerpted from the 45-megapixel Nikon Z7 or Nikon Z9, and you need to click them in order to see them full size. No sharpening has been applied except for light “sharpen for web” upon export from Lightroom.)
This is a very good result, considering the lack of sharpening. The detail on the bird’s neck is very well-defined and plenty sharp enough for a large print.
Here’s another example, this time with the subject closer to the edge of the frame:
And the 100% crop:
Although it’s a hair weaker than the previous photo, the feather details on the crane’s neck are still very sharp. With a bit of sharpening boost in post-processing, it would look seriously crisp.
Finally, a landscape photo. This image has more atmosphere between me and my subject, but the photo is still sharp up close, largely because I took it on a cold morning with less atmospheric distortion:
And a crop from the midframe:
This one may look a bit weaker, but note that the low-level details are still quite good – it’s more that there’s a general atmospheric haze robbing the contrast, which makes perceptual sharpness a bit lower than the actual sharpness. This is the sort of effect that you’ll often see when focusing in the distance with an 800mm lens.
Next up are the lab tests. Here’s how I measured the Nikon Z 800mm f/6.3 VR S in Imatest:
As you can see, f/8 is the sharpest aperture on the Nikon Z 800mm f/6.3 VR S throughout the frame, although I wouldn’t hesitate to use f/6.3 or f/11, either. I didn’t notice any focus shift or field curvature on this lens. The performance overall is very good, especially relative to most lenses in the corners. That said, we’ve tested lenses before which manage a higher Imatest score – usually at a wider aperture like f/4, which obviously isn’t possible on this lens.
I’ve used the Nikon Z 800mm f/6.3 with both of Nikon’s Z-series teleconverters, the 1.4x and 2.0x. They transform this lens into an 1120mm f/9 and a 1600mm f/13 respectively.
Starting with the 1120mm f/9, I wouldn’t call it the most practical lens on the market, but the sharpness is still acceptable. You’re running into a bit of diffraction at f/9, as well as sharpness issues with the lens and teleconverter itself.
Here’s an uncropped image at 1120mm and f/9:
Followed by an unsharpened 100% crop (also 2000 pixels wide for consistency). Click to see full-size.
I consider this to be very solid sharpness considering the strong crop, and of course the lack of sharpening in post-processing. If it looks dull, that may be because you’re used to the default sharpening applied in Lightroom or other software; the image doesn’t have that. As such, it can be improved quite a bit with some careful work in your preferred sharpening software.
Here’s an example where the subject was closer to the edge of the frame:
And the crop:
This performance isn’t perfect, and it’s a hair worse near the edges and corners, but it’s still pretty good. However, real-world photography at 1120mm runs into plenty of issues other than just lens sharpness: motion blur, atmospheric distortion, focusing issues, and so on. Even though the 800mm f/6.3 + 1.4x TC combo is acceptably sharp, your photos at 1120mm often may not be.
What about the 2.0x teleconverter? Now we’re getting ridiculous. A 1600mm f/13 lens simply isn’t a practical choice even in daylight conditions. Autofocus is very limited, and you lose some additional detail with the 2x TC. That said, it’s not awful in terms of sharpness if you really need this much reach. Here’s a matching 100% crop to show the sharpness. Click to see full-size:
This is better than I expected, even though it’s not as sharp as I’d like. If you desperately need a 1600mm lens for photographing, say, surfers at high noon from the distant shore, this combo could work – so long as you’re willing to deal with the autofocus issues and other challenges that arise.
I wouldn’t normally use this combination for everyday photography, but I found that it was viable for at least one popular subject. This photo is uncropped:
In terms of demonstrating the lens’s sharpness, a 100% crop of the photo above won’t be very useful, due to atmospheric distortion and the moon’s movement. But I’m sure that some people will be wondering anyway, and it’s still reasonably sharp, so here it is:
Unfortunately, our lens testing lab isn’t suited for testing any lens over about 800mm. I may still try it one day, but it’s probably a case where you should judge based upon real-world photos instead.
Bokeh is another word for the qualities of the background blur in a photo. “Good” bokeh is completely subjective, since different photographers have their own preferences for how the background blur looks. That said, photographers commonly want their background bur to be soft, not distracting. Out-of-focus highlights that are round, uniform, and soft-edged are usually preferable.
The bokeh qualities on the Nikon Z 800mm f/6.3 VR S are interesting, to say the least. Sometimes, the bokeh on this lens looks great. Other times, it looks pretty bad.
Let me explain what I mean. First, at 800mm, your background tends to be so far out-of-focus that it looks soft and dreamy no matter what. This hides a lot of the bokeh issues of the lens. Second, even when that isn’t the case, the bokeh on the 800mm f/6.3 VR S still looks good so long as there are no bright, specular highlights behind the subject.
Here’s a worst-case example:
And a crop:
That’s some shaky bokeh. Not only are the specular highlights highly textured, but some of them also have a sharply defined edge, and they’re taking on a bit of a “cat’s eye” shape. This definitely gets low marks from me.
But most of the time, the bokeh on this lens won’t look anything like that. Normally, the 800mm f/6.3 VR S renders bokeh more like this:
And a crop:
It’s still a little on the busy side, but nothing at all like the previous example – I’d characterize this as completely normal bokeh.
Finally, the following photo demonstrates both sides of the lens’s dual personality. Please excuse the uninteresting photo, and instead pay attention to the interesting bokeh (which occurred because the bird happened to fly in front of a car in the background):
If you don’t see it yet, here’s a tighter crop:
It’s noteworthy that the bokeh above looks totally fine except for the one bright, specular highlight where the sun was reflecting on the distant car. That single highlight has much more texture and definition – an effect that you’ll often see with very bright, out-of-focus specular highlights with this lens.
What’s causing this distracting texture? None other than the PF lens element. That’s right, the same thing that allowed Nikon to keep the lens’s weight and price relatively low has come back to bite us in bokeh. Fresnel lens elements like this one have a concentric texture to them, and that texture can appear directly in your background blur.
If you often find yourself shooting against the ocean or other subjects with lots of specular highlights, just be aware of the possibility of this distracting bokeh. Otherwise, I wouldn’t worry about it. For most wildlife photographers, the issue won’t appear in very many of your photos. Take a look at the photos throughout this review, and you’ll see that most of them have perfectly fine bokeh, even the ones with water in the background.
Spencer: It’s refreshing to test an S-series lens that isn’t optically flawless. Keeps me on my toes.
Nasim: But is this lens actually that bad? I’m not seeing anything to keep me from recommending it to someone.
Spencer: It’s sharp enough, and atmospheric distortion is a much bigger concern at 800mm anyway. The bokeh is another story and really depends on what subjects you shoot.
Nasim: To me, the issues of sharpness and bokeh on this lens are not something the typical photographer needs to worry about. Then again, the typical photographer is not spending $6500 on a lens.
The next page of this review dives into the sharpness numbers a bit more, with some comparisons against other lenses that Nikon users may be considering. So, click the menu below to go to “Lens Comparisons”:
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