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Dynamic Range (contd.)

Creative Style options

The graph below shows the dynamic range response from all of the A200's color Creative Styles. As you can see they all have slightly different tone curves but deliver similar amounts of dynamic range in the highlights. There is more variation in the shadow areas, so make sure you pick the right Creative Style if shadow detail is important in your shot.

ISO Sensitivity and Dynamic Range

As usual Dynamic Range reduces slightly towards very high sensitivities but overall DR is remarkably consistent across the ISO range.

Sensitivity Shadow range Highlight range Usable range
ISO 100 -5.1 EV 3.6 EV 8.7 EV
ISO 200 -5.2 EV 3.4 EV 8.6 EV
ISO 400 -5.2 EV 3.4 EV 8.6 EV
ISO 800 -4.7 EV 3.4 EV 8.1 EV
ISO 1600 -4.7 EV 3.5 EV 8.2 EV
ISO 3200 -4.3 EV 3.5 EV 7.8 EV

Dynamic Range compared

The dynamic range delivered by the A200 from its default tone curve is up with the best of its contemporaries, especially in the highlights. The ability to retain information in the highlights (above middle gray, approaching white) is often regarded as more useful for rendering a scene naturally than having more detail in the shadows because 'blown-out' highlights tend to be more distracting than loss of definition in dark regions of an image.

Camera
Shadow range
Highlight range
Usable range
Sony DSLR-A200 (ISO 100) -5.1 EV 3.6 EV 8.7 EV
Olympus E420 (ISO 100) -5.4 EV 2.8 EV 8.2 EV
Nikon D60 (ISO 100) -5.7 EV 3.3 EV 9.0 EV
Canon EOS 1000D (ISO 100) -5.2 EV 3.5 EV 8.7 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) 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 10.5 EV (just over one stop additional highlight range).

  • ACR Default: Exp. 0.0 EV, Blacks 5, Contrast +25, Curve Medium
  • ACR Best: Exp. -1.65 EV, Blacks 1, Brightness + 99, Contrast -50, Curve Linear




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 on the shirt but this comes with a blueish color cast as one or more of the color channels clips (There's also some quite impressive purple fringing from the kit lens in the bottom shot).


Adobe Camera RAW
default conversion
Adobe Camera RAW
-2.25 EV digital comp.



Adobe Camera RAW
default conversion
Adobe Camera RAW
-1.75 EV digital comp.
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