Nikon D40X Image Quality

Saturation & Hue Accuracy
Vibrant color with moderate oversaturation of strong reds and blues.

Saturation. The Nikon D40x produces images with fairly vibrant color, oversaturating strong red and blue tones. The oversaturation is a little higher that what we're used to seeing from a DSLR, but far from the most we've seen from consumer models. Relative to its little brother the D40, the D40x shows just slightly higher saturation across the board, and in particular avoids the D40's slight undersaturation of some greens and yellows. 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. Caucasian skin tones from the D40x lean toward the bright side, a bit more pinkish than in real life. Some users would call this "a healthy glow", others may find it a little ruddy. We found them acceptable, but generally prefer the somewhat more natural tones of the D40 over those of the D40x. Where color saturation is most critical is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, etc.

Hue. The Nikon D40x did push blue toward cyan a little (which produces better-looking skies), and oranges towards yellow, but again, the overall results are pretty good. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Auto White Balance does not compensate for tungsten lighting very well at all. Good color with the Incandescent white balance setting, though just slightly warm. Manual white balance is quite accurate. An average amount of exposure compensation was required.

Color balance indoors under incandescent lighting was pretty warm with the Auto white balance setting, though the Incandescent and Manual and options both produced more accurate results. In the end, the Incandescent setting was still just slightly too warm for our tastes, but some users may prefer this, as being more representative of the original lighting. The Nikon D40x required an average amount of positive exposure compensation here, at +1.0 EV. Despite the (very) slight warm cast, overall color with the Manual white balance setting looks quite good, though the blue flowers appear very purple. (Many digital cameras have trouble here.) 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
Bright colors overall, though a tendency toward a warm cast and high contrast under harsh lighting. About average exposure accuracy.

Outdoors, the Nikon D40x tended toward a warmer color balance, though overall color was generally pretty good. The D40x performed better than average in terms of exposure, requiring less than the typical amount of positive compensation we're accustomed to seeing among consumer digital cameras. (And the far-field shot of the house came out a little overexposed at the D40x's default exposure setting.) The D40x's default contrast is a little high, producing washed-out highlights and dark shadows under the deliberately harsh lighting of our "Sunlit" portrait test shown above left. The camera's contrast setting does tame the highlights and shadows slightly.

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Resolution
Very high resolution, 1,600 ~ 1,650 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,650 lines per picture height horizontally, and to about 1,600 vertically, with extinction past 2,000. 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. Our interpretation of this standard is somewhat conservative. We watch for artifacts and color fringing then move back to the nearest pure part of the scale. In our opinion, detail with artifacts shouldn't be considered detail. You may see other numbers quoted elsewhere, but across the site, our reviews judge this parameter by the same conservative standard.

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Sharpness & Detail
Reasonably sharp images overall, though slight edge-enhancement artifacts on high-contrast subjects. Some noise suppression also visible in the shadows.

Sharpness. The Nikon D40x captures fairly sharp images overall, though some minor edge enhancement artifacts are visible on high-contrast subjects such as the crop above left. (Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.)

Noise suppression. The crop above right shows some moderate noise suppression in the darkest areas of Marti's hair, though quite a few individual strands are visible in the lighter shadows. The camera's overall response here is better than average. 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.

ISO & Noise Performance
Low noise at the normal sensitivity settings, and fairly clean images at the higher settings.

Noise levels are quite low at the Nikon D40x's lower sensitivity settings. At ISO 800, noise is still low, but we start to see some loss in fine detail due to the camera's noise reduction. Noise levels increase at the 1,600 and 3,200 settings by quite a bit, with stronger blurring, "grain" and increased chroma noise, though results are still quite good for a 10 megapixel sensor at such high sensitivity settings. (We suspect most consumers would be pleased by 5x7 inch prints from the D40X's ISO 3200 files, and even 8x10s would look fine in a frame on a wall or table.)

Extremes: Sunlit and low light tests
High resolution with strong overall detail, but high contrast with strong highlights. Excellent low-light performance, great exposure to the lowest limits of our test, and the autofocus worked that low, even without the AF-assist light.

Sunlight. The Nikon D40x produced high contrast with slightly washed-out highlights and deep shadows under the harsh lighting of the test above. However, shadow detail is pretty good, despite some noise suppression and bright-pixel image noise. It's a bit of a toss-up here between the results at +0.3 and +0.7 EV. Some areas look a little hot at +0.7 EV, although many consumer-level users would doubtless prefer the brighter skin tones of that version. Skin tones in the image shot at +0.3 EV are a little dark, but the highlights are much better, with only the strongest of them being blown out. We'll "call" this as best at +0.3 EV, but recognize that some readers might prefer the versions a third-stop on either side of it. (In "real life" though, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.) The camera's contrast adjustment does help tame the high contrast here.

Note: 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.)

Low light. The Nikon D40x captured bright 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. The camera's autofocus system was also able to focus on the subject down to below the 1/16 foot-candle light level unassisted, which works out well for its exposure system. Do keep in mind though, that the very long shutter times necessary here absolutely demand the use of a tripod or other camera support to get sharp photos. (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.)

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.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.

Print Quality
Excellent print quality, great color, great 13x19 inch prints. ISO 1,600 images are soft but quite usable at 8x10, while ISO 3,200 shots are decent at 8x10 and very good at 5x7.

We were very pleasantly surprise by the original Nikon D40, and found ourselves very pleased by the results from the D40x as well. The D40x's additional resolution made for very nice-looking 13x19 inch prints, quite crisp and sharp looking. At high ISO, image noise levels are held in check surprisingly well up to the maximum of ISO 3,200 (!). We almost never say that, but it was true of the D40, and is true of the D40x as well. (The D40's larger pixels give it slightly less grain in areas of relatively flat tint, but the two cameras are very close to each other in high-ISO noise performance.) ISO 800 shots under daylight-balanced lighting look quite good at 11x14 and, those shot under incandescent lighting look great at 8x10, where images from most cameras will start to fall apart (the very warm color balance of incandescent lighting forces the camera's already-noisy blue channel to work harder, producing higher noise.)

Though they were somewhat noisy, even images from our severe incandescent-lit Indoor Portrait test produced usable prints up to 8x10 at ISO 1,600, working with those shot with Manual white balance. At ISO 3,200, the images showed yellow blotches in the skin and hair that showed up even at very small sizes. Still, a very impressive performance from a camera designed to be easy enough for novices to use.

Note: 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 i9900 studio printer, and on the Canon iP5200 here in the office. (See the Canon i9900 review for details on that model.)