Review Nikon D5100: Measurements

Resolution of the sensor

Dynamic range of the sensor

The Nikon D5100 performs a little less in terms of dynamic range than the Nikon D700. For a camera with an APS-C sensor, this performance is good however. The total dynamic range averages 12 stops for a RAW file and 11 stops for a jpg. For test method and explanation of terms, see FAQ. More important than the total dynamic range is the usable dynamic range, taking into account the signal/noise ratio.

Because the signal/noise ratio decreases in the shadows, the dynamic range of JPG files is limited to a usable dynamic range of 8 stops at the lower ISO settings up to three stops at ISO 6400. The jpg files apparently perform better, due to in-camera noise reduction, at all ISO settings than the RAW files. Yet that is not the case. We test the raw files without using noise reduction. Because of this, you maintain the highest possible detail in the shots, while the noise is, although measurable, not visible in a print. If you carefully optimize contrast, sharpening and noise reduction of RAW files, it is possible to realize a usable dynamic range for RAW files, which is better or equal to that of the jpg files.

Noise

Comparison of the noise in jpg files with the measured noise in RAW files without noise reduction shows that noise occurs at the jpg files at all ISO settings. We know from experience that if the noise is less than 2.5%, a photo can be printed on A3+ size without the noise being experienced as disturbing.

Below are examples of a photographed gray card at a variety of ISO settings. The croppings show a detail if you would show the image full size on your screen. By applying noise reduction, an even better result can be realized for RAW files. Up to 3200, you can make a good print from a RAW file without applying noise reduction.

Color accuracy @ daylight

The above illustration shows the color errors of the ISO 100 RAW shot taken in daylight. The further the ideal color (square) is removed from the color reproduction of the camera (circle), the greater the color difference. For the test method and explanation of terms, see FAQ. The Nikon D5100 delivers highly saturated RAW files with a reasonably good color rendition. In particular, the saturated yellow, orange and red colors are too saturated. Hold your mouse over the left image for a larger version. The measured saturation of RAW files is between 115 and 121%.

The accuracy of the color reproduction of JPG files is also pretty good. Depending on the ISO setting, the jpg files (standard) have an average color error (delta E94) between 6 and 11 and an average saturation of 102% with a peak down to ISO 25600 (93%).

Color accuracy @ tungsten light

The color reproduction is quite constant over the entire ISO range. In artificial light, you cannot blindly trust the automatic white balance, both with jpg and RAW files, as can be seen clearly in the results shown for a 200 ISO JPG file. All colors show an orange cast in artificial light, as you can also see in the practice image in the Nikon D5100 test.