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JPEG Tone Curves / dynamic range

Our Dynamic Range measurement system involves shooting a calibrated Stouffer Step Wedge (13 stops total range) which is backlit using a daylight balanced lamp (98 CRI). A single shot of this produces a gray scale wedge from the camera's clipped white point down to black (example below). Each step of the scale is equivalent to 1/3 EV (a third of a stop), we select one step as 'middle gray' (defined as 50% luminance) and measure outwards to define the dynamic range. Hence there are 'two sides' to our results, the amount of shadow range (below middle gray) and the amount of highlight range (above middle gray).

To most people highlight range is the first thing they think about when talking about dynamic range, that is the amount of highlight detail above middle gray the camera can capture before it clips to white. Shadow range is more complicated; in our test the line on the graph stops as soon as the luminance value drops below our defined 'black point' (about 2% luminance) or the signal-to-noise ratio drops below a predefined value (where shadow detail would be swamped by noise), whichever comes first.

Note: this page features our new interactive dynamic range comparison widget. The wedges below the graph are created by our measurement system from the values read from the step wedge, the red lines indicate approximate shadow and highlight range (the dotted line indicating middle gray).

In our tests the NEX-C3 shows about 4 stops of highlight range, which is quite impressive on its own. But the other thing to note is the gentle curve at the top of the highlight range which illustrates that images will show a more pleasing transition to 100% instead of harsh clipping. As you can see the tone curve used by the C3 is identical to other recent Sony cameras, including the NEX-3/5 and SLT-A55. This places it amongst the top of the class among interchangeable-lens cameras cameras, either mirrorless or SLRs.

Color Modes

The NEX-C3 has a range of color modes which have a relatively small effect on contrast - Vivid, Landscape and B&W all create images with slightly higher contrast for example, but with essentially the same highlight range. Portrait mode decreases the overall contrast which can be beneficial for creating smooth facial features without harsh shadows.

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