Nikon D3100 Image Quality

Saturation & Hue Accuracy
Very good color with only minor oversaturation and hue shifts in some colors.

Saturation. The Nikon D3100 pushes reds, blues and some greens a bit, but actually slightly undersaturates bright yellow and some cyans. Overall saturation levels are quite good, and less saturated than the previous D3000 model  (which was a little over-the-top in our opinion). The D3100's fine-grained saturation adjustment (see below) also makes it easy to customize its color to match your personal preference. 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 D3100's Caucasian skin tones looked just about right when using automatic white balance in simulated daylight. A very good job here. 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 D3100 did push cyan toward blue and red toward orange, 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.) With an average "delta-C" color error of only 4.81 after correction for saturation, overall hue accuracy was better than average. Hue is "what color" the color is.

Picture Control
The Nikon D3100 offers six preset "Picture Control" options. You can adjust Sharpening, Contrast, Brightness, Saturation and Hue for any of the settings. (For Monochrome, Saturation and Hue are replaced by Filter Effects and Toning settings.)

Saturation Adjustment
The Nikon D3100 has a total of seven saturation settings available, three above and three below the default saturation. This covers a pretty wide range of saturation levels, about as wide a range as you're likely to find photographically relevant, apart from special effects that are arguably better achieved in software. The fine steps between settings mean it's easy to program the camera to just the level of saturation you prefer.

The table above shows results with several saturation settings, see the Thumbnails index page for more (look for the files named D3100OUTBSATx.JPG). Click on any thumbnail above to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Good color with the Manual white balance setting, but overly-warm results with Auto and Incandescent. About average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance was very warm and reddish with the Auto white balance setting. (We'd say unacceptably so.) The Incandescent setting was a bit better, but 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 setting by far produced the most accurate results, if just a touch cool. The Nikon D3100 required an average amount of positive exposure compensation here, at +0.3 EV. The Nikon D3100 does not offer a Kelvin color temperature setting. 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.

Outdoors, daylight
Excellent results under harsh lighting, with very good handling of contrast, detail, and color.

Outdoors, the Nikon D3100 performed very well, though it required an average amount of exposure compensation of +0.7 EV for our "Sunlit" Portrait shot to keep the face reasonably bright. Contrast is a little high, as you might expect under such harsh lighting, but the camera did a very good job of holding onto detail in the highlights and deep shadows. Despite the bright appearance, there are relatively few clipped highlights in the model's shirt and the flowers. The Nikon D3100 overexposed the Far-field House shot at default exposure at bit, so we used -0.3 EV compensation for that shot. As you'd expect, there weren't many highlights blown in the Far-field House shot, and shadow detail is pretty good in all but the darkest shadows. Color balance is good as well, with good saturation considering the bright lighting. The camera's contrast adjustment and Advanced D-Lighting feature can further enhance highlight and shadow retention. (See the contrast adjustment series in the Extremes section below.) Overall, an excellent performance for its class here.

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

Resolution
Very high resolution, 1,800 to 1,900 lines of strong detail from JPEGs, slightly more from RAW.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,800 lines per picture height in the horizontal direction, and about 1,900 lines in the vertical direction. Extinction of the pattern didn't occur until around 2,600 lines in both directions. We weren't able to do much better in terms of absolute resolution with RAW files processed through ViewNX 2 or Adobe Camera RAW; perhaps just slightly more resolution in the horizontal direction. 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
Fairly sharp, detailed images with only minor edge-enhancement artifacts visible on high-contrast subjects. Only relatively minor noise suppression visible.

Sharpness. The Nikon D3100 produced very good detail overall when coupled with a sharp lens such as the Nikon 35mm f/1.8G prime used in the above left crop. Some very minor edge enhancement artifacts are visible on high-contrast subjects such as the crop above left, but overall results are excellent. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows some minor noise suppression, as the darker areas of the model's hair show good detail. Individual strands are still distinguishable even in the lighter shadows, though they begin to merge as contrast reduces. Still, 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 D3100 delivers fairly sharp, detailed JPEGs with only minor visible sharpening artifacts. However, more detail can often be obtained from carefully processing RAW files, without additional sharpening 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. Examples include in-camera Fine JPEG, and a RAW file processed through Nikon's ViewNX 2 software using default settings, and a RAW file processed with Adobe Camera RAW 6.3, then sharpened in Photoshop. We found that sharpening with 250-300% unsharp mask and a radius of 0.3 pixels worked well for the Nikon D3100's NEF files.

As you can see, results from a RAW file converted with Nikon's ViewNX 2 software were very similar to the in-camera JPEG, and the software wasn't really able to extract more detail, though contrast (and noise) is a bit higher at default settings. Adobe Camera RAW was able to extract quite a bit more detail, but also shows slightly higher noise levels as well as some chromatic aberration that the Nikon D3100 reduces in its JPEGs.

ISO & Noise Performance
Very good high ISO performance, with great detail vs noise handling up to ISO 1,600.

Noise levels are quite low at the Nikon D3100's lower ISO settings, and really quite good even at ISO 800. At ISO 1,600 noise levels increase with a touch more blurring in the fine details and visible "grain", but there are still loads of detail left to work with. At ISO 3,200, blurring is stronger with more noise-reduction artifacts, but the noise grain pattern is still quite tight and results compete well with the performance of DSLRs from other manufacturers at that ISO level, especially given the D3100's resolution and entry-level pricetag. ISO 6,400 and especially ISO 12,800 are quite noisy with purple and yellow blotchiness in darker areas, bright noise pixels, as well as much stronger blurring of fine detail, though sharpness and contrast are still fairly well maintained. Overall, a major improvement over the 10-megapixel Nikon D3000 despite the increase in resolution, with high ISO performance similar to Nikon's best 12-megapixel DX sensors. 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, usually 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. We know this; 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. :-) The focus target position will have been adjusted to insure that the rest of the scene is focused properly.

Extremes: Sunlit and low light tests
Very good detail in both highlights and shadows, high resolution and good overall exposure. Good low-light performance, capable of capturing bright images in near darkness.

Sunlight:
The Nikon D3100 handled the deliberately harsh lighting in the test above pretty well. Though contrast is a little high, shadow and highlight detail are both very good. The camera's contrast adjustment also did a good job of decreasing overall contrast without also affecting color saturation. (See below.) The +0.7 EV exposure did the best job here, as the model's face was too dim at +0.3 EV and +1.0 EV produced very strong highlights, though folks printing straight out of the camera will likely prefer the brighter face in the +1.0 EV shot. Be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.

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.)

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 D3100's contrast setting meets both challenges.

At its lowest contrast setting, the D3100 did a pretty good job of preserving highlight detail and bringing out shadow detail. Highlight retention was improved, but the contrast setting had a larger impact on opening up the shadows. The D3100 captures good color outdoors, though just slightly on the cool side in our Far-field House shot. The lower contrast setting helped to retain highlights and open-up shadows, without making the image too flat looking. Overall, very good results here.

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.

Nikon's contrast adjustment is that it has very little effect on 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 very good job here.

Nikon's Active D-Lighting
The shots above show the results with Active D-Lighting Off and On. (Like the D3000, the Nikon D3100 only has these two settings, while Nikon's more advanced models let you choose from a range of strengths of the effect). This is different than the touch-up menu's D-Lighting, as it is performed during image capture instead of after. (It does affect only JPEG images though, Nikon very properly leaves RAW file data strictly as it comes from the sensor.) Since very few highlights were blown at the default exposure (left), we've included results with +0.7 EV exposure compensation (right). Mouse-over the "On" links to see the difference, and click on the links to load the corresponding full-resolution image. As you can see from the images above, enabling Active D-Lighting results in improved shadow detail in both cases.

The effect of Active D-Lighting will vary quite a bit with the subject and lighting: The camera decides what needs adjusting, and by how much, so the effect can be quite a bit greater or lesser depending on what the camera sees. We almost always found ourselves pleased with the changes Active D-Lighting made, the main trade-off to using it being the longer time it takes the camera to process each photo. Automatic contrast-adjustment systems like this don't always produce natural-looking images, but Active D-Lighting seems to deliver consistently pleasing results. The system is not perfect, however, especially when adding exposure compensation to the mix. If you look closely at the +0.7 EV case, Active D-Lighting actually blew a few more highlights compared to when it was disabled. Shadow noise is also increased with Active D-Lighting on, but not by much, at least in these examples.

Above is another example of Nikon's Active D-Lighting at work, this time with our Far-field House shot in bright daylight. Again, mouse-over the "On" link to see the difference, and click on the links to load the full resolution images.

Here, we can see the effect of the Nikon D3100's Portrait Scene mode using the optical viewfinder, and face detection in Live View mode. As you can see from the shots above, the Portrait Scene mode made only a modest improvement to exposure, though default contrast has been toned down. But in Live View, Face-priority Autofocus mode made a huge difference, actually slightly overexposing the image.

Low light. The Nikon D3100 performed very well on the low-light test, capturing usable images at the lowest light level (1/16 foot-candle) with the lowest sensitivity setting (ISO 100). Auto exposure was a little off at the lowest light level (a fairly common occurrence in all but the best SLRs), so we used manual exposure for these shots. As you'd expect, noise increases as ISO goes up and light levels go down, but remains well controlled even at ISOs as high as 1,600. There's no sign of any banding issues or uncorrected hot pixel except at ISO 12,800 where you might expect to see those types of issues. Color balance is fairly neutral with the Auto white balance setting (just slightly cool), though it shifts towards a blue cast at lower light levels.

The camera's phase-detection autofocus system was able to focus on the subject down to just above the 1/8 foot-candle light level unassisted with the kit lens. That's not bad, but not quite as good as some SLRs. The Nikon D3100 was however able to autofocus in complete darkness with the AF assist enabled. In Live View mode, the camera's contrast-detect autofocus was only able to focus down to just below 1/2 foot-candle which is fairly typical, and AF assist is not supported in Live View mode.

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 D3100 do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
Excellent 20x30-inch prints; ISO 3200 shots are great at 13x19 inches; ISO 12,800 make crisp 5x7-inch prints.

Printed results from the Nikon D3100's standard JPEGs are quite good, starting with ISO 100 shots that print very well at 20x30 inches.

ISO 200 shots also look great at 20x30, though our laboratory Still Life shot is out of focus at that setting. Printing other ISO 200 shots, however, confirm its quality, as do the ISO 400 results.

ISO 400 shots are also excellent at 20x30 inches, with only slight softening due to noise suppression.

ISO 800 images are slightly soft, but strong detail is still present at 20x30 inches. Some luminance noise is present in the shadows. Detail softness becomes negligible at 16x24.

ISO 1,600 images are very nice at 16x24 as well, though more of the "processed look" appears around the edges and in the shadows. It's not noticeable at arm's length, though. Reducing print size to 13x19 removes most signs of processing.

ISO 3,200 files print very well at 13x19 inches, though shadows and dark objects start to lose some detail as contrast increases.

ISO 6,400 images are better printed at 11x14 inches, though shadows and colors appear darker. All of this looks more natural printed at 8x12 inches, with only very high saturation and contrast being an issue.

ISO 12,800 look good, but with a watercolor painting effect at 8x12 inches. 5x7-inch prints, though, look excellent in terms of detail, though contrast and shadows are darker and deeper.

Overall, the Nikon D3100 turns out impressive images, pretty well on-par with the Canon 60D in terms of ISO performance. Standard JPEGs start out with high saturation and end with very high contrast in their prints, but the D3100 offers some adjustment to both. The only noise reduction options are On and Off, plus RAW, but those should be sufficient for most consumers, as the D3100's printed output can be categorized as "satisfying" in a way that most people will appreciate.

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 Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)