Nikon D5000

	Noise Summary
• Top performer in our comparison group • Noise reduction filter highly effective without severe loss of image detail • Standard ISOs range from 200-3200, expanded range 100-6400
	Color	Page 4 of 21	Resolution

Noise (6.83)

The Nikon D5000 delivered better image noise performance than any of the other cameras in our comparison group, though the camera-to-camera differences aren't dramatic.

We test for image noise, the annoying speckles that resemble film grain from days of yore, by shooting the X-Rite ColorChecker chart at all of the official (i.e, not extended range) ISO settings under bright studio illumination, and analyze the resulting images using Imatest software. We shoot at each noise reduction level, all of which factor into the final noise score. While ramping up the noise reduction level inevitably leads to a loss of fine detail, we were pleased to see the D5000 suffered far less of a problem here than many other cameras. To visualize the relationship between higher noise reduction levels and loss of image detail, see the Sample Photos section. Click here for more on how we test noise.

The following chart shows the effect of each noise reduction level across the full range of official ISOs. Even with noise reduction off entirely, image noise never rises beyond 2%, and the Normal level keeps noise at about 1% even out to ISO 3200.

Noise Reduction Level Comparison

Shown here are the individual noise components: red, green, blue, yellow and luma (gray). If these are widely spread, imperfections can be visible even if a camera has a low overall image noise score. In this case, that's not a problem.

Color & Luma Noise

The following two charts compare image noise levels for each tested ISO level, first with noise reduction off (and image detail at its highest), the second with noise reduction at its highest setting. While there isn't an enormous performance spread here, the D5000 does significantly outperform the Pentax and Rebel T1i across the board, and the tough ISO 1600 level proves to be a sweet spot for this camera.

Noise Reduction Off Comparison

With noise reduction cranked all the way up the D5000 produces extraordinarily clean images at high ISO settings. If you need to grab available light photos in challenging conditions, you're going to welcome this polished performance, even if it does cost a bit of fine-line sharpness.

Noise Reduction Maximum Comparison

As seen in the score comparison graph below, the Nikon D5000 holds a small overall edge when all noise reduction levels are considered.

Noise Score Comparison

NOTE: We updated our testing and scoring procedures in January 2009. For comparison purposes, we re-tested several cameras we'd reviewed in 2008, producing the scores shown in the chart above for the Canon Rebel XS and Nikon D90. However, the scores in the original reviews for these re-tested cameras remain unchanged, for consistency's sake.

ISO (6.00)

As with most Nikon cameras, the D5000 has a range of official ISOs, indicated numerically in the menus, plus additional extended ISO settings above and below. In this case, the official ISOs run from 200 to 3200. The lower extended range settings are Lo 0.3, equivalent to ISO 160, Lo 0.7 (ISO 125) and Lo 1 (ISO 100). On the high side there are Hi 0.3 (ISO 4000), Hi 0.7 (ISO 5000) and Hi 1 (ISO 6400). Why not just treat all the ISO settings equally? Because, as Nikon points out, the Hi settings are subject to increased image noise and color distortion, while the Lo settings have lower contrast.

In addition to the standard controls there is an Auto ISO setting, used in Auto shooting mode and by default in scene modes. When shooting in program, shutter-priority, aperture-priority or manual modes, turning the Auto ISO setting on will only affect exposure if the camera determines that an appropriate exposure can't be achieved at the ISO setting chosen by the shooter. A maximum allowable value when shooting in Auto ISO mode can be set.

The table below displays same-size crops taken from still life photos taken with each of the comparison cameras across the range of available ISOs.

	ISO Examples
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 100
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 200
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 400
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 800
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 1600
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 3200
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 6400
	Nikon D5000	Canon Rebel T1i	Canon Rebel XS	Nikon D90	Pentax K2000
ISO 12800

NOTE: The images above are not used in our testing or scoring, but are included here to show real-world examples of the differences between cameras at the various ISO settings.