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Dynamic Range

Creative Style options

The graph below shows the dynamic range response from all of the A380's Creative Styles. They all have slightly different tone curves but deliver similar amounts of dynamic range. While all styles clip at the same point in the highlights the Portrait and Night settings produce just a tad more shadow range than the Standard style.

ISO Sensitivity and Dynamic Range

The dynamic range remains essentially unchanged across the ISO range. The apparent increase in shadow dynamic range at high ISO is due to the camera producing too much shadow noise and therefore our test algorithm being incapable of finding a black point on the test image.

Sensitivity Shadow range Highlight range Usable range
ISO 100 -5.2 EV 3.5 EV 8.7 EV
ISO 200 -5.2 EV 3.5 EV 8.7 EV
ISO 400 -5.4 EV 3.4 EV 8.8 EV
ISO 800 -5.1 EV 3.5 EV 8.6 EV
ISO 1600 -5.8 EV 3.4 EV ~ 8.5 EV*
ISO 3200 -7.7 EV 3.5 EV ~ 8.5 EV*

*The smeared noise pattern of the A380 appears to be confusing our analysis calculations into believing that data is being recorded when the image itself has been reduced to a baseline level of smoothed-out noise. There is not any more information is actually being recorded than at lower ISO settings.

Dynamic Range compared

The A380's measured dynamic range is more or less in line with the current crop of entry-level DSLRs. It delivers 3.7 EV of highlight range (at ISO 100 and without any software trickery, unlike for instance the Olympus E-620) which should help keeping blown out highlights under control. For most users this is more useful for rendering a scene naturally than having more detail in the shadows.

Camera
Shadow range
Highlight range
Usable range
Sony DSLR-A380 (ISO 100) -4.9 EV 3.7 EV 8.6 EV
Canon EOS 500D (ISO 100) -5.1 EV 3.4 EV 8.6 EV
Nikon D5000 (ISO 200) -4.8 EV 4.0 EV 8.8 EV
Olympus E620 (ISO 200) -5.3 EV 3.9 EV 9.2 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).





RAW headroom

Experience has told us that there is typically around 1 EV (one stop) or more 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 with previous reviews we settled on Adobe Camera RAW for conversion to retrieve the maximum dynamic range from our test shots.

As you can see the default Adobe Camera RAW conversion delivers less dynamic range than JPEG from the camera (a more contrasty tone curve and less noise reduction in shadows). The best we could achieve was 11.9 EV of total dynamic range. However, this only includes 0.8 EV of extra highlight range.

  • ACR Default: Exp. 0.0 EV, Blacks 5, Contrast +25, Brightness 50
  • ACR Best: Exp. -0.95 EV, Blacks 0, Contrast -50, Brightness 80, Curve linear

Settings
Usable range
JPEG

8.6 EV

ACR Default
7.3 EV
ACR 'Best'
11.9 EV

WARNING: 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 clouds and the dress respectively but this soon turns into gray and/or shows a color cast as one or more of the color channels clips. All in all, after playing with a number of RAW files, it's probably fair to say that there is some extra information in the A380's headroom but you'll struggle to get any extra detail beyond a negative exposure compensation of 1 EV.


Adobe Camera RAW
default conversion
Adobe Camera RAW
-1.45 EV digital comp.


Adobe Camera RAW
default conversion
Adobe Camera RAW
-2.6 EV digital comp.
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