Image parameters

The Optio 750Z provides just three levels of adjustment (-1 to +1) for each of the contrast, saturation and sharpness image parameters. This is sadly lacking compared to some other competitive cameras and doesn't really provide the photographer which very much control over the final look of the image. It's a pity Pentax couldn't provide a wider latitude or finer level of adjustment.

Image parameter adjustments

  • Contrast: -, 0, +
  • Saturation: -, 0, +
  • Sharpness: -, 0, +


Adjusting the tone alters the shape of the 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.

  Contrast Luminosity histogram




Saturation adjustment allows you to control the strength of color in the final image. As you can see the minus and plus settings provide a fairly strong swing in color response, once more a finer level of adjustment would have been more beneficial.

  Saturation 100% Crop


The 750Z's default sharpening setting is sufficient although does introduce some slight halo artifacts, the minus setting is pretty soft and the plus setting is too harsh.

Sharpness: -
Sharpness: 0
Sharpness: +