Nikon D4 Exposure

Saturation & Hue Accuracy
Good color and accurate saturation.

Saturation. The Nikon D4 pushes dark blues and some darker greens moderately, but actually undersaturates yellow, light green and cyan tones slightly. Overall, saturation levels are quite accurate, only 4.7% oversaturated at ISO 100, which is lower than most SLRs. The D4's default saturation generally increases with ISO, except at 204,800, where it is slightly lower. 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 D4's Caucasian skin tones looked realistic in outdoor lighting 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 produced slightly pinker results. 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 D4 showed a few small color shifts relative to the mathematically precise translation of colors in its subjects, but its overall color accuracy was good. Reds were shifted slightly toward orange, cyan was shifted toward blue, and there were slight shifts in orange, green and purple, but shifts were relatively minor. (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 4.87 after correction for saturation, which is about average for a professional SLR these days. Hue is "what color" the color is.

Saturation Adjustment
The Nikon D4 lets you adjust the 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. There is also an Auto setting available that produced results very similar to the default for this scene. See the Thumbnails index page for more (look for the files named D4OUTBSATx.JPG). Click on any thumbnail above to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Very warm results with Auto and Incandescent white balance, though excellent color balance with Manual and 2,600 Kelvin settings. About average exposure compensation required.*

Indoors, in common incandescent lighting, color balance was very warm and reddish with the Auto white balance setting. (We'd say unacceptably so.) The Incandescent setting was also too warm and yellowish for our tastes. (Some users may prefer this look, though, as being more representative of the original lighting.) The Manual white balance setting produced accurate results, as did the 2,600 Kelvin color temperature setting (which matches the temperature of our lights in this scene). The Nikon D4 required about average exposure compensation for this shot (+0.3 EV). 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 D4 is one such body (as was the D7000, D90 and D300S), as the exposure compensation settings actually used in the images above are lower than normal for this shot. Accordingly, the comments regarding exposure compensation required have been adjusted to match results we achieved with a Nikkor lens. Other than this exposure shift, 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 somewhat high default contrast. Options like Active D-Lighting and contrast adjustment are a help when faced with tough conditions like these.

The Nikon D4 handled tough outdoor lighting under harsh sunlight reasonably well, producing good overall exposure and color. We found skin tones a touch pale in our "Sunlit" Portrait shot with Auto white balance though, so we preferred Manual WB. Default contrast was on the high side (as most users prefer), so a few highlights were clipped in the model's shirt, pendant and some of the flowers while darker shadows were quite deep, though shadow noise is quite clean if a little yellow/green in this shot. No exposure compensation (0 EV*) was required to keep the mannequin's face reasonably bright, which is much better the +0.7 EV average for this scene. The Far-field shot was well exposed at 0 EV, with only a few highlights clipped in white areas. Again, detail in the shadows was very good, and shadow noise very low.

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

Resolution
Very high resolution, ~2,100 to ~2,200 lines of strong detail from JPEGs, about the same from converted RAW files.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,100 lines per picture height in the horizontal direction, and 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 2,600 to 2,800 lines. We weren't able to extract much more resolution with RAW files processed through Adobe Camera Raw 6.7 rc1. We did notice the ACR conversion contained much more color moiré than the in-camera images so the camera's processing is doing a pretty good job. 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 with relatively minor edge-enhancement on high-contrast subjects. Minimal noise suppression artifacts at base ISO.

Sharpness. The Nikon D4 produced sharp, detailed images for a 16-megapixel sensor, with only minor edge enhancement artifacts visible on high-contrast subjects such as the larger branches in the crop above left. Overall, default sharpness is good, if a little on the conservative side (as most pros would prefer). 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 model's hair show a lot of detail. Individual strands are still distinguishable even in the lighter shadows, though they begin to merge as shadows deepen, and in places where the tone and color of adjacent strands is very close. All in all, a very good 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 D4 does a pretty good job at capturing lots of detail in JPEGs A little more detail can be obtained from carefully processing RAW files, though, without introducing additional artifacts. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking the link will load the full resolution image. Examples were shot at ISO 100, and compare an in-camera Fine JPEG to the matching RAW file processed through Adobe Camera Raw (ACR) version 6.7 rc1. For the converted image, we found best results by disabling sharpening in ACR, and sharpening instead in Photoshop with 250% unsharp masking with a 0.3 pixel radius, though some may prefer slightly lighter sharpening.

As is frequently the case, the demosaicing in Adobe Camera Raw and sharpening in Photoshop deliver finer detail than the camera. Looking very closely at the images, ACR extracts a bit more detail that wasn't present in the JPEGs from the camera itself, but the main difference is in the fineness of the rendering. While they don't look as crisp, the Nikon rendering is smoother-looking and if you look very closely, there's less visible noise, though noise is by no means an issue with the D4. Still, we'd personally go the Adobe (or other high-quality third-party RAW converter) route here if we were concerned about making the sharpest-looking print possible from the D4's files. That said, the D4's in-camera JPEGs are really quite good, and you can always try adjusting in-camera sharpening to your tastes.

ISO & Noise Performance
Excellent handling of noise vs detail to ISO 3,200, with good performance up to ISO 12,800.

The Nikon D4's JPEG noise performance is slightly improved over its predecessor, the D3S, which is a remarkable achievement given the smaller photosites. Images are very clean at ISOs 50 through 800, which 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. 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, though chroma noise is more noticeable. At ISO 12,800, subject detail is still quite good, much better than average at such a high ISO. ISO 25,600 is noticeably less detailed than those at lower sensitivity levels, with more visible noise reduction artifacts, though still usable. ISO 51,200 and above show a lot more chroma noise, in the form of yellow and purple blotches which also shifts white balance towards yellow. Some horizontal banding is also noticeable at ISO 51,200 and up.

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
Very high resolution with good highlight and shadow detail. Excellent low-light performance, capable of capturing bright images in near darkness.

Sunlight:
The Nikon D4 handled the deliberately harsh lighting fairly well in the above test. Though contrast is a little high, highlight and shadow detail are very good. The camera's contrast adjustment also did a good job of decreasing overall contrast without producing strong color variations; see the section below. The default "0 EV" exposure* did the best job here, though the mannequin's eyes were a bit dim. (Most pros would likely prefer the 0 EV exposure here, as lighter exposures clipped too many highlights, though some may prefer the +0.3 EV for printing straight from the camera.) A few highlights were blown in the model's shirt and flowers at 0 EV, but fewer than we're used to seeing, while good detail was preserved in the shadows with lower than average noise. Note that these shots were captured with the Nikon D4'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 D4'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 D4 did a good job of preserving highlight detail, maintaining natural-looking skin tones, and bringing nice detail out of the shadows. Overall, very good results here, especially when the contrast setting is tweaked. (This is a really tough shot; the Nikon D4 does a better than average job handling it.)

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. There is also an Auto setting available. 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 available on the Nikon D4 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, however, are 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 default exposure. Click on a 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 to better show how each setting compares.)

As you can see from the thumbnail images and histograms above, higher settings of Active D-Lighting 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 sensor, so increased shadow noise is not much of a concern here.

See below for how Active D-Lighting worked with our Far-field shot.

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 trim of the house as the strength of Active D-Lighting is increased. The Auto setting did a pretty good job here.

HDR Mode
The D4 marks the second Nikon SLR to offer an in-camera high-dynamic-range imaging function (the D5100 was the first), something we've seen in several DSLRs from competing manufacturers for a while now. When enabled, the D4 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). We don't believe the Nikon D4 performs micro-alignment of the two images even though the user manual warns of possible cropping. If it is, it can only correct for very small amounts of camera movement between shots, and so Nikon recommends the use of a tripod. Obviously moving subjects should also be avoided.

Like the D5100, the Nikon D4 allows you to set the exposure differential between the two images from 1, 2 or 3 EV, and there's an Auto setting where the camera decides. There is also an option to adjust the amount of "smoothing" that is applied to the boundaries between the two images, with selections of Low, Medium and High. One difference from the D5100 is the D4 adds an option to capture a Single HDR image as well as an On/Off toggle for shooting a series of HDR images. (The D5100 only offers On/Off.)

Mouse over the links above to see how various levels of HDR affects our "Sunlit" Portrait shot and click on a link to get to the full-res image. As you can see, the higher levels make quite a difference to the overall exposure by opening up shadow detail and toning-down highlights while at the same time reducing shadow noise, but lower levels of smoothing can lead to artificial looking shadows around bright objects or halos and glowing around dark ones. Colors can also be adversely affected in HDR mode, such as a drop in saturation. Still, it's a useful feature for capturing static scenes with dynamic range that exceeds the sensor for those not willing to use manual HDR techniques (bracketing exposure and then combining images while post-processing).

Dynamic Range
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)

What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work. A full discussion of all the data Imatest produces is really beyond the scope of this review: Visit the Imatest website for details of what the program measures, how it performs its computations, and how to interpret its output.

JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera D4 JPEG file with a nominally-exposed density step target (Stouffer 4110). At default settings and base ISO, the graph shows 10.8 f-stops of total dynamic range, with 7.86 f-stops at the "High" quality level. These are very good numbers for in-camera JPEGs. Compared to the Nikon D7000 which was Nikon's top dynamic range performer before the D4 was released, the D4 scored slightly lower at the "High" quality level (7.86 vs 7.97 f-stops), though total dynamic range scored better (10.8 vs 10.0 f-stops). Note though that this measurement has a margin of error of about 1/3 f-stop, so differences of less than 0.33 can be ignored.

RAW. The graph at right is from the same Stouffer 4110 stepchart image captured as a RAW (.NEF) file, processed with Adobe Camera Raw using the Auto setting. The Nikon D4's RAW file scored 1.8 f-stops more in total dynamic range than the JPEG (12.6 vs 10.8 f-stops) and the score at the highest quality level increased 2.34 f-stops from 7.86 to 10.2 f-stops. This is an excellent score, among the best cameras we've tested to date. Again, results are very similar to those of the Nikon D7000, with nearly the same High Quality score (10.2 vs 10.1 f-stops) though the D4 scored higher in total dynamic range (12.6 vs 12.1 f-stops). It's worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the High Quality threshold. Also, the extreme highlight recovery being performed by ACR here would likely produce color errors in strong highlights of natural subjects.

Low Light. The Nikon D4 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). As is usually the case, the D4's metering system struggled a bit with getting the exposure right at the lowest levels though, so we used manual exposure for these shots. Color balance with Auto white balance is fairly neutral at higher light levels, but took on an increasingly stronger magenta cast as light levels dropped and ISO increased. Noise is quite low up to ISO 12,800, and even at higher ISOs there's still a lot of detail to work with when high ISO NR is set to "Off" (which still applies some noise filtering at ISO 3,200 and above). The Nikon D4 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 Normal NR setting, and Long Exposure NR was enabled so it was applied to exposures longer than one second. We didn't find any issues with hot pixels, but some horizontal banding is visible at ISO 25,600 and above. 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.

The camera's phase-detection autofocus system was able to focus on the subject down to below the 1/16 foot-candle light level unassisted with an f/2.8 lens. The Nikon D4 doesn't have a built-in AF illuminator, but can utilize the AF illuminator found on compatible flash units. In Live View mode, the D4's contrast-detect autofocus was able to focus down to just above the 1/16 foot-candle, which is very good.

(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 D4 do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality

ISO 50 through 200 shots look good printed at 30 x 40 inches from normal viewing distances. On close inspection, you can however see slight jaggies. As a result, we think this is the upper limit of this 16-megapixel sensor, although larger prints are possible for wall display purposes.

ISO 400 shots look essentially the same printed at 30 x 40, though there's a hint of soft chroma noise in the shadows, so we'll call 24 x 36 officially "good" here.

ISO 800 images look good at 20 x 30, with a slight softening that's still acceptable and minor noise in flatter areas.

ISO 1,600 images are better at 16 x 20, as slight chroma noise blobs start to form in the shadows and there's a minor loss in sharp detail at 20 x 30. This all tightens back up at 16 x 20 inches.

ISO 3,200 shots are better printed at 13 x 19, thanks to heavier grain in the shadows and continued loss of detail.

ISO 6,400 shots look fairly good at 11 x 14 inches for less critical applications, despite a slight increase in luminance noise in the shadows, but it's 8 x 10s that we can give our official seal of approval to. High-contrast detail is still remarkable at this size, and the red leaf swatch still has very good definition, where most cameras would have resorted to a blurred red field.

ISO 12,800 images are good at 8 x 10, again for less critical applications, despite the continued increase in contrast. At 5 x 7, luminance noise is under control, and detail is very good.

ISO 25,600 shows good detail and controlled shadow noise when printed at 5 x 7, though there is minor noise in the shadows.

ISO 51,200 is a bit rough for printing at 5 x 7, but makes a very good 4 x 6.

ISOs 102,400 and 204,800 are not suitable for printing and are best avoided.

With quite excellent printed results straight out of the camera, the Nikon D4 fulfills Nikon's goal of maintaining impressive low light performance in a high-speed reporter's camera.

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.)