Image parameters

Like previous Pentax digital SLR's the K100D provides two 'tone' options of Bright (the default) and Natural. These define the color mapping, tone and sharpening baseline for image processing. As with other Pentax implementations we preferred the Natural setting with a little extra sharpening and saturation, the Bright option can lead to over saturated color (especially reds).

In addition to the Tone baseline you can also adjust Contrast, Saturation and Sharpness.

Image parameter adjustments

  • Tone modes: Bright, Natural
  • Color space: sRGB, Adobe RGB
  • Image parameter adjustments
    • Contrast: -2 to +2
    • Saturation: -2 to +2
    • Sharpness: -2 to +2

Image tone

As mentioned above the image tone setting provides a baseline for the other image parameters, you can directly compare the color response of these two settings later in our Photographic Tests section, below are a few crops to demonstrate the differences between these two options.

Bright Natural

Image tone resolution / sharpness difference

Note that there does also appear to be a subtle drop in sharpening going from the Bright to Natural tone, although it's not significant enough to lead to any loss of detail or resolution (in fact if anything it helps to avoid sharpening halos).

Bright Natural

Contrast adjustment

Adjusting the tone alters the shape of the 'S curve' used to map the linear image data captured by the sensor into the correct gamma. A lower contrast setting maintains more of the original data's dynamic range but leads to a flatter looking image. A higher contrast setting stretches the grayscale (dark to light) of the image and could lead to clipping of both shadow detail and highlights. The K100D provides a fairly good latitude of adjustment although a little further in each direction wouldn't have done any harm.

  Thumbnail Luminosity histogram

Color saturation adjustment

Saturation adjustment allows you to control the strength of color in the final image. It's quite amazing that Pentax could ignore something we pointed out over a year ago when we reviewed the *ist DS, that the default saturation level is way too high. In my opinion the '0' setting should be mapped to '+2' and the '-2' setting would be just right as a default. The K100D's -2 setting (in the Bright tone) has about as much saturation as a +1 setting on any other digital SLR. (Default Bright tone used here).

  Thumbnail 50% crop


While not the most crisp images we've seen the K100D's default sharpening level is about right, if you prefer your images a little sharper you can always opt for the +1 setting. Remember that selecting the Natural tone will deliver lower sharpening. (Default Bright tone used here).

Sharpness: -2
Sharpness: -1
Sharpness: 0 (default)
Sharpness: +1
Sharpness: +2