Nikon D90

Noise
What we call noise in digital photography is very much like the grain we used to see when shooting film – tiny speckles and imperfections, most visible when looking at areas of flat color, particularly when shot under low lighting. You probably won't notice noise in a photo blown up to snapshot size, but start printing at larger sizes, cropping and enlarging a smaller section of an image to full-size or applying aggressive image editing filters and algorithms and problems with image noise can become severe.

We test a camera's noise performance by shooting our color chart under bright studio lighting conditions, which shouldn't pose much of a challenge, at the full range of available ISO settings, and running the resulting images through the appropriate Imatest analysis module. Noise is also a key factor in scoring low-light performance, which is tested separately.

Noise – Manual ISO (10.48)
The D90 produced impressive results in our noise testing, starting out below 0.7% and maintaining less than 1% noise right through ISO 640. While scoring in this section is based on the camera's performance with its high ISO noise reduction circuitry turned off, the chart shown here demonstrates how effectively the Nikon system works. The D90 provides three levels of noise reduction and, at the highest setting, noise remains essentially flat right across the ISO spectrum. Of course, other characteristics waver when the image is heavily processed to suppress noise, including color accuracy and shooting speed, but low-light photographers should still be pleased with the flexibility and performance offered here.

In our cross-camera comparisons, only the surprisingly strong Nikon D60 surpassed the results from the D90.

Auto Noise (1.91)
Sad to say, the D90 stubbed its hypothetical toe on a test it was ill suited to take. Our testing procedure calls for setting the camera to automatic ISO, letting the camera's digital brain set the ISO sensitivity, then measuring the image noise in the resulting photo. For some strange reason, the Nikon only allows automatic ISO selection in its highly authoritarian Auto mode, which effectively takes away control of nearly all the camera settings and turns it into a $1000 point-and-shoot. Nothing wrong with having this option, though we'd prefer being able to use auto ISO selection in the more flexible Program mode as well, which allows far more user control. This was not to be, though. And shooting in full Auto mode, the D90 chose an extraordinarily high ISO 900 in a brightly lit environment, producing a malodorous score in the process.

Looking at our comparison chart, we can see that the Olympus E-520 suffered similar digital brain freeze during our auto noise testing procedure. On the bright side, most Nikon D90 shooters are likely sophisticated enough to set their own ISO and enjoy the significant benefits of this minimal effort.

Low Light (9.27)
The ability to take good-looking photos in low-light conditions without flash is one of the key reasons to step up to more full-featured cameras, with their higher-sensitivity image sensors, superior lenses and more advanced noise reduction software. Even among similarly priced models, though, we continue to find significant performance differences. To quantify these variations we test low-light performance based on varying light levels and exposure times, analyzing color accuracy and image noise performance.

In our first test, we set the camera to ISO 1600 and shoot the Gretag-Macbeth color chart at four levels of illumination, ranging from  60 lux (approximately the light level you’d find in a normal indoor setting) down to 5 lux (about what a single candle would provide). The test is undertaken at each available high ISO noise reduction setting.

The D90 maintained very good color accuracy at all four lighting levels, and image noise was well controlled at the relatively high ISO 1600 setting. Even with the noise reduction system turned off, noise peaked at about 1.4%. At the default Normal noise reduction setting, it barely broke the 1% mark.

In our second low-light test, we shoot the color chart at ISO 400 at exposure times ranging from 1 second out to 30 seconds, with long-exposure noise reduction on and off. Here again, we were very pleased with the D90 performance, maintaining a very steady, low-noise result across the board.

 

Averaging the two test results to get an overall score, we find the D90 surpasses all of the other cameras shown here, with a significant performance boost over the less-expensive D60 model.

Nikon D90 Low Light Scores

Still Life
We shoot the same two still-life setups at the full range of available ISO settings for each review, providing the opportunity to compare and contrast performance both across an individual camera’s range, and across camera models. The lighting consists of standard household fluorescent bulbs, and the camera is set on automatic mode. Since the D90 offers thirteen ISO settings, plus Lo and Hi ranges, we've chosen eight representative shots to feature below. Clicking on an image below will bring up the full-resolution original, but be forewarned: these are large files and can take some time to download.

 

Video Performance (9.00)
With its large image sensor and sharp, full-size Nikon lens, we expected D90 video performance to surpass your basic point-and-shoot camera, and we weren't disappointed. Color accuracy was fairly wonky compared to the camera's performance when shooting stills, but the image noise results were very impressive, even in low light.

In our first video test we illuminate the color chart to a bright 3000 lux, grab still frames from the resulting file and test for color and image noise performance. We left the camera on Auto for this test, as we would with a point-and-shoot, though it's worth noting that the D90 does allow for manual adjustments for color, white balance and other image parameters. These tests are run with standard-resolution video settings, in this case 640 x 424,

Color and Resolution	Page 4 of 15		Speed and Timing
Nikon D90 Digital Camera Review Navigation
Intro	Physical Tour	Color and Resolution	Noise and Video
Speed and Timing	Components	Design / Layout	Modes
Control Options	Image Parameters	Connectivity / Extras	Overall Impressions
Conclusion	Sample Photos	Specs / Ratings