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 |  |
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| 0 |  |
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| +3 |  |
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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 |  |
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| 0 |  |
 |
| +3 | |
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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 |  |
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| 0 |  |
 |
| +1 |  |
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| +2 |  |
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