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 cameras) black to clipped white (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' 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 the camera can capture before it clips to white. Shadow range is more complicated, in our test we stop measuring values below middle gray 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 graph below shows the dynamic range response from each of the E-30's five Picture Mode presets (there is a custom setting in addition to this). As you can see each has a slightly different tone curve but none achieves any better highlight range. By a small margin the best overall range (because of its lighter and hence extended shadow range) comes from the Muted setting.
The E-30's gradation setting produces images in low or high keys, it does so by modifying the tone curve as well as the exposure (around a third of a stop under for Low Key and a third of a stop over for High Key). To show the difference in tone curve more clearly for this graph we adjusted the exposure manually. As you can see the Low key pulls down the shadows a little, whereas the high key pushes up the highlights a little. Overall dynamic range remains roughly the same. However, the auto mode does some serious lifting of the shadows and can introduce noise and result in rather flat images. As ever we'd recommend using RAW+JPEG when allowing the camera to apply such radical image adjustments.
The E-30, in common with other Olympus DSLRs, allows you to apply this shadow lifting trick to JPEGs in-camera (you can also use it in Olympus Studio). To see how the Shadow Adjustment Technology lifts the shadows in a typically challenging shot see the two images below:
|Default JPEG (Gradation Normal)||
Shadows adjusted in-camera
Here we have tested the extremes of the contrast setting from -2 to +2. As you can see the -2 setting does indeed deliver quite a bit more shadow range (because it lifts steps above our cut-off point) but does not extend highlight range (which clips at around +3.8 EV, the same as the default contrast setting).
ISO Sensitivity and Dynamic Range
When looking at the graph below it becomes clear that, like on the E-3, ISO 200 appears to be the 'optimal' sensitivity setting on the E-30 (the true base ISO). At ISO 100 the highlight range is reduced by more than one stop It's important to keep this mind when shooting in bright conditions, especially as it is not properly documented in the manual (in fact the only clue is that Auto ISO starts at ISO 200). However, the good news is that at ISO 200 the E-30 offers approximately 2/3 of stop more highlight range than the E-3 which is a significant improvement and puts the E-30 in the same ballpark as other cameras in its class.
|Sensitivity||Shadow range||Highlight range||Usable range|
|ISO 100||-5.7 EV||2.7 EV||8.4 EV|
|ISO 200||-5.1 EV||3.8 EV||8.9 EV|
|ISO 400||-4.7 EV||3.9 EV||8.6 EV|
|ISO 800||-4.3 EV||3.8 EV||8.1 EV|
|ISO 1600||-3.7 EV||3.8 EV||7.5 EV|
|ISO 3200||-2.7 EV||3.8 EV||6.5 EV|
Dynamic Range compared
The graph below shows that at ISO 200 the E-30 does well with shadow detail and now also offers a highlight range that is almost on par with the best in class in JPEG (as we see below, in the RAW Headroom section, the JPEGs make use of almost everything the sensor has to offer, unlike most SLRs).
The wedges below 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).
Experience tells us that there is typically around 1-2 EV (one to two stops) of extra information available at the highlight end in RAW files and that a negative digital exposure compensation when converting such files can recover detail lost to over-exposure.
The E-30 is, like previous E-System cameras, unusual in that there isn't a great deal of headroom in the raw files. There is only approximately half a stop of extra highlight information in the RAW file compared to the JPEG output. On the one hand this means Olympus' JPEG engine is doing a pretty good job, using almost all the information that is available in the highlights. On the other hand it means you won't be able to recover much from blown highlights, even when shooting RAW.
- ACR Default: Exp. 0.0 EV, Blacks 5, Contrast +25, Brightness 50, Curve Medium
- ACR Best: Exp. -0.95 EV, Blacks 0, Contrast -50, Brightness 70, Curve Linear
WARNING: When looking at the graph above it's important to bear in mind is that although ACR was able to retrieve the 'luminance' (brightness) of wedge steps which were previously clipped there's no guarantee of color accuracy as individual channels may clip before others (see below).
As can be seen in the examples below it is possible to recover some highlight detail with negative exposure compensation in RAW conversion but often this results in color issues. While some detail is recoverable there is hardly any color information in this extra highlight range.
|ACR default conversion||ACR with -1.8 EV digital exp. comp.|
|ACR default conversion||ACR with -1.85 EV digital exp. comp.|