Nikon D4S Exposure

Saturation & Hue Accuracy
Vibrant colors with slightly below average hue accuracy.

Saturation. The Nikon D4S pumps dark blues a lot, dark greens moderately, quite a few colors slightly, but actually undersaturates yellow, light green and cyan tones a bit. Overall, mean saturation levels are a little higher than average at 14.5% oversaturated at ISO 100 versus a more typical 10%. The D4S's default mean saturation is fairly consistent at low to moderately high ISOs, but decreases at very high ISOs, with a minimum of 106% at 409,600. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. The Nikon D4S's rendering of Caucasian skin tones look realistic in "sunlit" outdoor lighting when using auto white balance, just slightly on the pale side. (Likely because the camera doesn't pump reds as much as most.) Manual white balance produces more healthier-looking pinkish tones. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Nikon D4S produces a few color shifts relative to the mathematically precise translation of colors in its subjects. Reds are shifted slightly toward orange, and cyan toward blue, but there are only slight shifts in yellow, orange, green and purple. (The cyan to blue shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) Mean "delta-C" color error at base ISO was 7.01 after correction for saturation, which is a little higher than average (lower numbers are better), but still considered good, and remains around 7 across the ISO range. Hue is "what color" the color is.

Saturation Adjustment
The Nikon D4S lets you adjust image saturation and contrast in seven steps each, brightness in three steps, hue in seven steps and sharpening in ten steps. There are also Auto settings for saturation, contrast and sharpening. As can be seen below, the saturation adjustment worked very well, providing a reasonably fine-grained adjustment over a useful range of control. The saturation adjustment also has almost no impact on contrast. That's how a saturation control should work, but we've often found interactions between saturation adjustments and image contrast (and vice versa) on the cameras we test.

The series of shots above shows results with several different saturation adjustment settings, showing the minimum step size around the default, as well as both extremes. See the Thumbnails index page for more (look for the files named D4SOUTBSATx.JPG). Click on any thumbnail above to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Warm results with Auto and Incandescent white balance, though excellent color balance with Manual and 2,600 Kelvin settings.

Indoors, in common incandescent lighting, color balance is warm and reddish with the Auto white balance setting. The Incandescent setting is very warm with a strong yellow tint. (Some users may prefer this look, though, as being more representative of the original lighting.) The Manual white balance setting produced accurate results, and the 2,600 Kelvin color temperature setting (which matches the temperature of our lights in this scene) also did quite well. We can't really comment on exposure accuracy, as the Nikon D4S doesn't play nicely with our third-party Sigma 70mm reference prime when it comes to exposure (see below). Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Note: These shots were captured with a Sigma 70mm f/2.8 macro lens, one of the sharpest lenses we've ever tested on SLRgear.com. We use Sigma 70mm lenses in most of our studio test shots because they are so sharp and are available for most major platforms. For some reason, though, on some (but not all) Nikon bodies, the Sigma causes the camera's exposure system to overexpose by somewhere between one third of a stop and a full stop depending on the aperture. The D4S is one such body (as was the D4, D7000, D90 and D300S), as the exposure compensation settings actually used in the images above are lower than normal for this shot, while others are higher. Other than exposure shifts, the Sigma 70mm performs very well on Nikon bodies, so we continue to use it as our "reference" lens, due to its excellent optical qualities.

Outdoors, daylight
Good color and exposure outdoors, but high default contrast. Options like Active D-Lighting and contrast adjustment are a help when faced with tough conditions like these.

The Nikon D4S handled tough outdoor lighting under harsh sunlight fairly well. We found skin tones a touch pale in our "Sunlit" Portrait shot with Auto white balance though, so we preferred Manual WB (even though the shot above left is slightly front-focused). Default contrast is on the high side, so quite a few highlights were clipped in the mannequin's shirt, pendant and some of the flowers while darker shadows are quite deep, though shadow noise is very low. We can't really comment on exposure accuracy for our "Sunlit" Portrait shot because of the Sigma lens compatibility issue. The Far-field image on the right was shot with a Nikkor 50mm is just slightly overexposed with a few clipped highlights in very bright white areas and in specular highlights. Again, detail in the shadows is very good, and deep shadow noise is remarkably low. Color here with Auto white balance is very pleasing.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, ~2,200 to 2,300 lines of strong detail from JPEGs, about 2,300 lines from converted RAW files.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,300 lines per picture height in the horizontal direction, and to about 2,200 lines per picture height in the vertical direction in JPEGs. (Some might argue for higher, but aliasing artifacts begin to appear at those resolutions.) Complete extinction of the pattern didn't occur until around 2,800 to 3,000 lines. We were able to extract a bit more resolution with RAW files processed through Adobe Camera Raw 8.4, perhaps 100 lines vertically, while complete extinction was extended past 3,200 lines in both directions. The ACR conversion contained more color moiré than the in-camera JPEG images, though, so the camera's processing is doing a pretty good job suppressing it. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Very good detail for the resolution, though default sharpening and contrast is a bit higher than the D4. Minimal noise suppression artifacts at base ISO.

Sharpness. The Nikon D4S produced very sharp, detailed images for a 16-megapixel sensor at default settings, though edge enhancement artifacts are more visible compared to the D4 around high-contrast subjects, such as the sharpening halos around the lines and lettering in the crop above left. Default sharpening is higher than we're used to seeing for a pro Nikon DSLR, but you can always turn it down if you prefer. (And you can always adjust sharpening to your liking.) Edge enhancement creates the illusion of sharpness by enhancing color and tonal differences right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows only minimal detail loss due to noise suppression, as the darker areas of the mannequin's hair show a lot of detail. Individual strands are still distinguishable even in the lighter shadows, though some begin to merge as shadows deepen, and in places where the tone and color of adjacent strands is very close. The hair is also virtually free from chroma noise, which is often not the case. An excellent performance here. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

RAW vs In-Camera JPEGs
As noted above, the Nikon D4S does a great job at capturing lots of fine detail in its JPEGs, but more detail can often be obtained from carefully processing RAW files, while at the same time reducing sharpening artifacts. Let's have a look at base ISO:

In the table above, we compare an in-camera JPEG taken at base ISO using default noise reduction and sharpening (on the left) to the matching RAW file converted with Adobe Camera Raw 8.4 using default noise reduction with some strong but tight unsharp mask sharpening applied in Photoshop (250%, radius of 0.3 pixels, and a threshold of 0).

As is frequently the case, the demosaicing in Adobe Camera Raw and sharpening in Photoshop deliver finer detail than the camera, with fewer sharpening artifacts. Looking very closely at the images, ACR extracts a bit more detail that isn't present in the JPEGs from the camera itself, even in the red-leaf swatch Nikons do very well with. The ACR conversion manages to resolve some of the thread patterns in the fabrics while the camera treats them as noise and blurs them away. While they don't look quite as detailed, Nikon's rendering is smoother-looking with higher contrast and more vibrant color, and if you look very closely, there's a touch less visible noise, though noise is by no means an issue with the D4S. Still, we'd personally go the Adobe (or other high-quality third-party RAW converter) route here if we were concerned about making the best images possible from the D4S's files. That said, the D4S's in-camera JPEGs are excellent and you can always try adjusting image processing settings to your tastes.

ISO & Noise Performance
Very good detail versus noise up to ISO 12,800!

The Nikon D4S' JPEG noise performance is improved compared to its predecessor, the D4, with slightly lower chroma noise along with slightly higher luminance noise, the latter likely just the result of higher default sharpening.

Images are very clean at ISOs 50 through 800, with just a touch of luminance noise becoming more visible in the shadows as ISO increases. Performance at ISOs 1,600 and 3,200 is very good, with excellent detail retention despite slightly higher noise levels. Detail is still very good at ISO 6,400, with a tight film-like noise "grain" and very little fine detail lost to noise reduction. At ISO 12,800, subject detail is still quite good, much better than average at such a high ISO. ISOs 25,600 and 51,200 are noticeably less detailed than lower sensitivity levels, with more visible noise reduction and sharpening artifacts, though still quite usable. ISO 102,400 and above show a a lot of luma noise accentuated by sharpening artifacts, as well as lot more chroma noise in the form of yellow and purple blotches. Some horizontal banding is also noticeable at ISO 51,200 and up. ISO 204,800 is swamped by noise and sharpening artifacts while ISO 409,600 is a bit of a joke with very strong noise, obvious sharpening artifacts and a purple-blue tint in shadow areas.

All in all, though, amazing high ISO performance, probably the best we've seen thanks to the D4S's larger than average photosites and revised image processing.

Of course, the impact of noise and detail loss are highly dependent on the size the photos are printed at, and pixel-peeping on-screen has surprisingly little relationship to how the images look when printed: See the Print Quality section below for recommended maximum print sizes at each ISO.

A note about focus for this shot: We shoot this image at f/4, using one of three very sharp reference lenses (70mm Sigma f/2.8 macro for most cameras, 60mm f/2.8 Nikkor macro for Nikon bodies without a drive motor, and Olympus Zuiko 50mm f/2.0 for Four Thirds and Micro Four Thirds bodies). To insure that the hair detail we use for making critical judgements about camera noise processing and detail rendering is in sharp focus at the relatively wide aperture we're shooting at, the focus target at the center of the scene is on a movable stand. This lets us compensate for front- or back-focus by different camera bodies, even those that lack micro-focus adjustments. This does mean, though, that the focus target itself may appear soft or slightly out of focus for bodies that front- or back-focused with the reference lens. If you click to view the full-size image for one of these shots and notice that the focus target is fuzzy, you don't need to email and tell us about it; we already know it. :-) The focus target position will simply have been adjusted to insure that the rest of the scene is focused properly.

Extremes: Sunlit, dynamic range and low light tests
High resolution with very good shadow detail, though contrast is high blowing some highlights. Excellent low-light performance, capable of capturing bright images in near darkness.

Sunlight:
Surprisingly, the Nikon D4S struggled a little with the deliberately harsh lighting in the above test, because of its somewhat high default contrast. We felt "+1.0" EV exposure compensation (remember that the Sigma lens doesn't expose properly, so less exposure compensation is likely needed with a Nikkor) was required to keep the mannequin's face bright, but that led to quite a few blown highlights in her short and flowers. (And apologies for the slight front focus on that shot.) Pros would likely prefer "+0.7" EV or even "+0.3" EV and brighten the image in post (or just shoot RAW), thereby holding on to highlight detail that the "+1.0" EV exposure lost. Since shadows and midtones are quite clean, boosting shadows isn't really a problem in terms of noise. Note that these shots were captured with the Nikon D4S's Active D-Lighting control set to its default of "Off." See below for how Active D-Lighting and contrast settings help with hot highlights and deep shadows.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)

Contrast Adjustment
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. Just as with its saturation adjustment, the Nikon D4S's contrast setting meets both challenges, the contrast steps actually being a little finer than those for saturation, and thus even more to our liking.

At its lowest contrast setting, the D4S did a good job of bringing nice detail out of the shadows and also preserved highlight detail better, while maintaining natural-looking skin tones.

The series of shots above shows results with several different contrast adjustment settings, showing the minimum step size around the default, as well as both extremes. While you can see the extremes, it's hard to really evaluate contrast on small thumbnails like these, click on any thumbnail to go to the full-size image.

One very nice feature of Nikon's contrast adjustment is that it has very little effect on color saturation. Contrast and saturation are actually fairly closely coupled, it's a good trick to be able to vary one with out the other changing as well. As usual, Nikon did a good job here.

Active D-Lighting
Active D-Lighting attempts to preserve detail in both highlights and shadows in high-contrast situations, while maintaining moderate levels of contrast. The series of shots below show the effect of the various Active D-Lighting settings (Off (default), Low, Normal, High, Extra High 1, Extra High 2 and Auto) available on the Nikon D4S on our high-contrast "Sunlit" Portrait scene.

Note that Active D-Lighting is different from the Retouch menu's D-Lighting, as it is performed during image capture instead of after. (It does affect only JPEG images, though, Nikon very properly doesn't apply tonal adjustments like this to RAW file data. NEF files are however tagged so that Nikon software can automatically apply the effect when converted.)

Mouse over the links to see how the various levels of Active D-Lighting affects our "Sunlit" Portrait shot at "+0.7 EV" exposure, and click on any link to get to the full-res image. (Active D-Lighting's effect can be a little subtle in shots like those above, so we decided to use a mouse-over with matching histograms to better show how each setting compares.)

As you can see from the thumbnail images and histograms above, higher Active D-Lighting settings did a very good job at preserving highlights while bringing up shadows and deeper midtones, without making the image look too flat. Normally, there is a noise penalty to be paid for boosting shadows, but noise levels in the shadows are very low with this camera, so increased shadow noise is not a concern here at base ISO. It's also interesting to note that the default ADL setting for the D4S is Off, while in more consumer-oriented models, the default is Auto.

Here are the results with our Far-field shot. As you can see, Active D-Lighting brought up shadow detail while holding on to highlights. Also note the slight blue cast in the white pillars and trim of the building as the strength of Active D-Lighting is increased. The Auto setting did a pretty good job here.

HDR Mode
Like other recent Nikon DSLRs, the D4S offers an in-camera high-dynamic-range imaging function. When enabled, the D4S captures two images with one push of the shutter button -- one underexposed and one overexposed -- and combines them in-camera to produce a high-dynamic-range JPEG. (RAW format is not supported.) There are three exposure differentials available: 1, 2 and 3 EV, as well as an Auto option, and there are three Smoothing options: Low, Normal and High. You can also elect to do a series of HDR shots without having to re-enable the mode each time, or select a Single Photo option.

Mouse over the links to see how the Auto, 1 EV and 2 EV levels of HDR with default Smoothing as well as 3 EV with Low, Normal and High Smoothing affects our Far-field shot at default exposure. Click on a link to get to the full-res image.

Obviously moving subjects should be avoided, as you can see from the ghosting in the flags in some of HDR shots above. Aside from the noticeable halos and "glowing" caused by the Low Smoothing option, we think Nikon D4S's in-camera HDR is one of the better implementations.

Dynamic Range Analysis (RAW mode)
While we once performed our own dynamic range measurements based on in-camera JPEGs as well as converted RAW images (when the camera was supported by Adobe Camera Raw), we've switched to using DxO Labs' results from their DxOMark website. As technology advanced, the dynamic range of modern high-end cameras in some cases exceeded the range of the Stouffer T4110 density scale that we used for our own measurements. DxO's approach based on RAW data before demosaicing is also more revealing, because it measures the fundamental dynamic range of the sensor, irrespective of whatever processing is applied to JPEGs, or to RAW data by off-the-shelf conversion software.

In the following, we use DxO's "Print" dynamic range results, which are scaled based on camera resolution. As the name suggests, this scaling corresponds to the situation in which you print at a given size, regardless of how many megapixels the camera might have. (In other words, if you've decided to make a 13x19 inch print, that's the size you're printing, whether the camera's resolution is 16 or 300 megapixels.) For the technically-minded, you can find a discussion of the reasoning behind this here on the DxOMark website. Also note that DxO Labs uses a signal-to-noise (SNR) threshold of 1 when defining the lower boundary of acceptable luminance noise in their dynamic range measurements, which corresponds to the "Low Quality" threshold of the Imatest software we used to use for this measurement.

Here, we compare the Nikon D4S' dynamic range to that of its predecessor, the D4, and to its closest competitor, the Canon 1DX. As you can see from the above graph (click for a larger image), the D4S's dynamic range is just slightly better than the D4 at the ISO 100 setting (13.31 EV vs 13.1), but the older model does a bit better at ISO 200 through 1,600, however the D4S retakes the lead with slightly better performance (up to about 1/2 stop better) at ISO 6,400 and above. The D4S's dynamic range is however more than 1.5 stops better than the Canon 1DX's at base ISO (13.31 vs 11.77), though at ISO 3,200 it's the same, and at higher ISOs the D4S is only very slightly better. Click here to visit the DxOMark page for the Nikon D4S for more of their test results and additional comparisons.

Low Light. The Nikon D4S performed very well here, able to capture usable images down to the 1/16 foot-candle light level (about 1/16 as bright as average city street lighting at night) at all ISO settings, though lower light levels at ISO 50 are a bit dim because of the 30 second shutter speed limit (Bulb mode is required for longer exposures).

Color balance with Auto white balance is fairly neutral at higher light levels, just a touch cool, but took on an increasingly stronger magenta cast as light levels dropped and ISO increased, as we've seen with other Nikons.

Noise is well controlled up to ISO 25,600, and even at higher ISOs there's still a lot of detail to work with, especially when high ISO NR is set to "Off" (which still applies some noise filtering at ISO 6,400 and above). The Nikon D4S gives you four options for high ISO noise reduction: Off, Low, Normal, and High, so you have some flexibility in deciding how much noise to trade for detail. Except for the "No NR" shots in the table above, these were all shot using the default NR setting, and Long Exposure NR was enabled so it was applied to exposures longer than one second.

Some horizontal banding (pattern noise) is visible at ISO 25,600 and above, and there's also a purple tint emanating from the bottom right at very high ISOs indicating some heat blooming, likely from a warm component nearby. Longer exposures at lower ISOs may show similar heat-blooming discoloration. We didn't notice any issues with hot pixels.

The camera's phase-detection autofocus system was able to focus on our test subject down to well below the 1/16 foot-candle light level unassisted with an f/2.8 lens, which is excellent. The Nikon D4S doesn't have a built-in AF illuminator, but can utilize the illuminator found on most compatible flash units. In Live View mode, the D4S's contrast-detect autofocus was able to focus down to just above the 1/4 foot-candle, which is fair.

(Keep in mind that the longer shutter speeds here demand the use of a tripod to prevent any blurring from camera movement. A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Digital SLRs like the Nikon D4S do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality

Excellent 30 x 40 inch prints at ISO 50-400; very nice 20 x 30s at ISO 1600; good 11 x 14s at ISO 6400; nice 8 x 10s at ISO 25,600!

ISO 50 through 200 prints look terrific at 30 x 40, with excellent detail and rich colors. The prints -- especially at ISO 50 and 100 -- have a very three-dimensional quality. Wall display prints at these settings look great up to the huge 40 x 60 inch print.

ISO 400 also produces a very good 30 x 40 inch print and is excellent for this sensitivity and size. Wall display prints are quite good up to 36 x 48 inches.

ISO 800 yields a very good 24 x 36 inch print, with virtually no apparent noise anywhere in the image. This is one of the nicest ISO 800 prints that we've had the pleasure of viewing.

ISO 1600 images look great at 20 x 30, remaining sharp even in our mosaic tile area. Again, quite an impressive and rare feat for this sensitivity.

ISO 3200 prints a very nice 16 x 20. It's amazing to note that at this sensitivity that you have to print out a 20 x 30 to see virtually any noise. At 16 x 20, letters in the Pure bottle are still nice and clear, and colors still pop nicely. Impressive!

ISO 6400 produces 13 x 19s that are fairly nice, with only minor noise in flatter areas, and almost make our "good" rating. 11 x 14s show virtually no noise at all, and retain rich colors and good detail. This is the first sensitivity level where the D4S begins to appear anything but otherworldly in its abilities.

ISO 12,800 yields 11 x 14s that almost make our "good" rating. With just a bit too much noise in general, they still have full color and nice detail, usable for most applications. To be safe, we'll call 8 x 10s good here.

ISO 25,600 prints an 8 x 10 that still makes the grade for a good print, and that is entering rare territory indeed. 11 x 14s show definite signs of noise in some areas of our test target, and less detail in finer areas and our tricky red swatch, but are still usable for many applications!

ISO 51,200 produces a good 5 x 7 inch print. At this sensitivity, that is quite an achievement -- and doubly so when you consider that the D4 could only yield a 4 x 6 inch print.

ISO 102,400 does not yield a print that we can rate as "good", although 4 x 6 is really not bad here, so if a small print is all you need you may still be able to get a decent result.

ISO 204,800 and 409,600 do not yield good prints, and these settings are best avoided for any applications.

It seems there is a new sheriff in town for low light performance, and his name is Nikon D4S. Besting the beloved D4 at every sensitivity setting beyond ISO 400, the D4S goes where few cameras have gone before. A terrific 20 x 30 at ISO 1600? No problem. A nice 11 x 14 at ISO 6400? Again, no sweat. A good 8 x 10 at ISO 25,600? Wow.

Suffice it say that your printer will love you for purchasing this camera, as will your display walls. The three highest sensitivity settings aren't really usable, but from ISO 51,200 on down, you'll be in low-light heaven.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 Mark II studio printer, and on the Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)