Our new 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.
Film Mode setting
The DMC-L1 has seven preset film modes, four in color and three black and white. As you can see from the graph below the first three (Standard, Dynamic and Nature) demonstrate subtly different tone curves (as each has a slightly different contrast setting) the last, Smooth, is significantly different with darker midtones and less of a 'roll off' in highlights. Changing the Film Mode (or contrast) settings makes no difference to highlight range / the 'clip point'.
ISO Sensitivity and Dynamic Range
The DMC-L1 delivers a better than average 8.5 EV (eight and a half stops) of dynamic range at ISO 100 which drops only slightly at ISO 200. Highlight range extends nicely to 3.3 EV with a visible roll-off, shadow range all the way down to -5.2 EV at ISO 100. At higher sensitivities dynamic range becomes limited by increasing shadow noise, although highlight range remains the same.
|Sensitivity||Shadow range||Highlight range||Usable range|
|ISO 100||-5.2 EV||3.3 EV||8.5 EV|
|ISO 200||-5.0 EV||3.3 EV||8.3 EV|
|ISO 400||-4.3 EV||3.3 EV||7.6 EV|
|ISO 800||-3.7 EV||3.3 EV||7.0 EV|
|ISO 1600||-2.7 EV||3.3 EV||6.0 EV|
Dynamic Range compared
The DMC-L1 demonstrates a very similar overall dynamic range to the Canon EOS 30D with the same highlight range and roughly the same shadow range, in fact the only noticeable difference is the shape of the tone curve. With the same sensor the Olympus E-330 delivers slightly less highlight and shadow range, this could be due to a more contrasty tone curve.
|Camera (ISO 100)||Shadow range||Highlight range||Usable range|
|Panasonic DMC-L1||-5.2 EV||3.3 EV||8.5 EV|
|Olympus E-330||-4.8 EV||3.1 EV||7.9 EV|
|Canon EOS 30D||-5.1 EV||3.3 EV||8.4 EV|
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 EV (one stop) 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.
As is fairly typical you get about an extra one stop of highlight information and potentially even more a the shadow end. However see our caveat below about highlight detail maintaining color.
- ACR Default: Exp. 0.0 EV, Shadows 5, Bright. 50, Contrast 25, Curve Medium (Default)
- ACR Best: Exp. -1.25 EV, Shadows 0, Bright. 70, Contrast -50, Curve Linear
WARNING: One thing 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.
This can be seen fairly clearly in the examples below, on the right the negative digital exposure compensation has revealed some more detail in the sky and roof but there is no color information so the sky turns from cyan to gray.
|ACR default conversion||ACR with -2.00 EV digital exp. comp.|