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 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).

Cameras Compared

The chart below shows the X-E2's default tone curve, in comparison to some of its immediate peers.

The X-E2's default tone curve is less 's-shaped' than most of its peers, meaning it gives 'flatter,' more even contrast across most of its tonal range, then clipping to white and black rather abruptly, rather than offering higher mid-tone contrast and reducing contrast near the top and tail of the tone curve. There's some 'roll-off' in the shadow regions.

In terms of highlights, at its DR 100% setting, it performs reasonably well. The DR 200% option makes things a lot more competitive, while the DR 400% setting captures more highlight range than our test chart can simulate. The 5EV above middle grey offered by the DR 400% mode is difficult to incorporate into an image without the results looking unnatural or 'flat,' so we find DR 200% is usually suffiecient for most real-world shooting.

Tone curve options

The X-E2 allows you independently adjust the shadow and highlight regions of its tone curve, allowing you to increase or decrease contrast in those areas. This allows you to more closely match the tonal response of earlier X-Series cameras (which had slightly lower-contrast shadow responses), if you wish. Interestingly, the 'Soft' highlight setting shows a fraction more highlight range than the other two settings - suggesting the camera is clipping a little earlier than it needs to.

These adjustments can be combined with the camera's DR modes, either at the point of shooting or later, using the in-camera Raw converter. You can also adjust overall brightness in the Raw converter which, in conjunction with the tone curve tweaks, gives a good degree of flexibility to help you get a JPEG you're happy with.

New tone curve

When we reviewed the X100S, some readers expressed concern that the camera's default tone curve clipped more aggressively to black than the X-Pro1. If you compare the X-E2's standard, 'Provia,' setting to the X-Pro1's version, you can see this is still the case. Interestingly, though, the tone curve is almost exactly the same as the X-Pro1's 'Astia/Soft' setting. On the X-E2 the 'Provia/Standard' and 'Astia/Soft' settings now use essentially the same tone curve - the difference between these modes is now just one of color response, not contrast.

The X-Pro1 Provia tone curve can't be precisely imitated on the X-E2 through the use of the Shadow Tone setting (since it affects everything from immediately below middle grey, whereas the X-Pro1 Provia only differed in terms of the deeper shadows). However, if you're looking for that gentler, lower-contrast look, the X-E2's Pro Neg. Std film mode offers the same contrast but with a different, more muted color response.