Sony Alpha NEX-F3 Review
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.
The most important thing to note on this graph is the curve at the top of the highlight range. The gentleness of the curve illustrates the NEX-F3's ability to render highlights with a pleasing curve to 100% brightness instead of clipping off. As you can see the F3's default tone curve is all but identical to the 5N as well as other recent Sony cameras. The F3's dynamic range performance is among the top of its class.
The NEX-F3 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.