Image parameters contd.

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. Sony provides 7 settings in total (though as the images below show, the actual range of the contrast control isn't huge).

  Thumbnail Luminosity histogram
-3
0
+3

Brightness adjustment

Adjusting the brightness appears to shift the mapping of the 'black point' which could be useful for 'lifting' shadows on a bright day or delivering a more definite black in a studio situation.

  Thumbnail Luminosity histogram
-3
0
+3

Zone adjustment

The zone adjustment enables you to perform zone matching which effectively stretches or compresses the shadow or highlight areas of the grayscale. Use a negative setting to lift shadows for low-key shots or a positive setting to compress (and maintain) highlights for high-key shots. You can see this in effect in the histograms below.

  Thumbnail Luminosity histogram
-1
0
+1
+2