Better Light 7 manual Tone Curve Histogram, Selecting an Output Tone Scale

Tone Curve Histogram

While the Tone panel is active, a histogram of the image data appears in a gray color in the tone curve graph. The shape of this histogram is different from the one in the main window because it is based on the raw 14-bit image data, not the converted 8-bit data shown in the prescan image. The tone curve histogram does not change when the Normalize Histogram option is turned on or off in the Display menu. This histogram does not change with a change in crop area but will change with tone or exposure changes.

Selecting an Output Tone Scale

The grayscale used to represent the output value scale on the left side of the tone graph can be used to change the way the tone graph is represented. By default, the tone graph is shown with dark output values toward the bottom of the graph, light values near the top. Clicking on the grayscale will change the graph to show light values near the bottom of the graph and dark values near the top. This will not invert the image. As you may note, when the scale is inverted, the curve also inverts, so the relationship of output values to input EV values remains the same; only the graph is changed.

Setting the EV Scale Reference

The zero position on the EV scale can be set to any position within the range of the camera. This is accomplished by clicking and dragging the zero point on the scale to any position, left or right, within the graph. This new position will be the reference point for the EV readout in the tone graph and the live spot meter display above the histogram in the main window. Once the zero position has been moved, it remains at the new position until moved again or ViewFinder™ is quit. When ViewFinder™ is quit, the EV scale zero point will be reset to its default position when ViewFinder™ is restarted (the EV scale zero point is not saved in the Preferences file).

When using the contrast adjustment buttons on the Tone tab panel, you can hold the Option key down and it will pivot the curve at the zero position of the EV scale.

All live spot meter readings in the prescan can be easily referenced to a particular point with this feature. Select the reference point in the prescan image and set a static spot at the point. Then posi- tion the zero point on the tone curve graph EV scale to the spot meter reference point marked by the colored square on the tone curve. All live meter readings will now be relative to the marked static spot meter. The meter can be cleared with the Clear Meter command and subsequent live meter readings will continue to be relative to the previously marked spot.

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