Dynamic Range (contd.)

Image Tone option

The K200D provides a range of selectable image tones which define the tone curve, color saturation and sharpening. All options provide roughly the same shadow range, Vibrant and Portrait give you a tad (approximately 1/3rd of a stop) more highlight range.

ISO Sensitivity and Dynamic Range

The K200D's performance in the highlights is pretty constant across the ISO range although not particularly impressive. Approximately three stops is not quite up there with the best in class and means you'll end up with more blown highlights than you'd like. There's quite a lot of detail in the shadows though. So in critical situations you could slightly underexpose to preserve the highlights and then pull up the shadows in post-processing. Don't overdo it though, otherwise you'll get too much noise in the dark parts of the images.

Sensitivity Shadow range Highlight range Usable range
ISO 100 -6.0 EV 3.0 EV 9.0 EV
ISO 200 -6.0 EV 3.0 EV 9.0 EV
ISO 400 -5.7 EV 3.2 EV 8.9 EV
ISO 800 -6.3 EV 3.1 EV 9.4 EV
ISO 1600 -5.1 EV 3.0 EV 8.1 EV

Dynamic Range compared

As mentioned above the K200D's highlight range is slightly below par. At base ISO it's slightly better than the Olympus E-520 but can't quite keep up with the EOS 450D (Digital Rebel XSi) and the Nikon D60.

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 from the graph and wedges below Adobe Camera RAW in default mode actually returns a little less dynamic range, a combination of a more contrasty tone curve and more noise in shadow areas means it is cut-off by our 'lowest acceptable SNR'. The best we could achieve (with some pretty extreme ACR settings) was 10 stops total dynamic range, and more importantly about a stop more highlight range (although with no guarantee of color accuracy).

  • ACR Default: Exp. 0.0 EV, Shadows 5, Bright. 50, Contrast 25, Curve Medium (Default)
  • ACR Best: Exp. -0.85 EV, Shadows 0, Bright. 70, Contrast -25, 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 (see the slight greenish cast in the bottom right crop).

An extra stop of RAW headroom allows you to recover some blown highlights (see bottom image) but can't do any miracles as you can see on the tree below. Even three stops of negative digital exposure compensation only bring a small amount of highlight detail back to the blown out bark.

Adobe Camera RAW
default conversion
Adobe Camera RAW
-3.00 EV digital comp.

Adobe Camera RAW
default conversion
Adobe Camera RAW
-2.05 EV digital comp.