Advanced use of the Curve Tool
September 28, 2011 6 Comments
The Curve Tool in Capture One is a very powerful tool for precise control of the tone mapping of an image. Even though the Exposure Tool also provides sliders for controlling the tone mapping, you sometimes need a more advanced tool to achieve a specific goal.
You can use the “Pick Curve Point” cursor tool to place a point on the curve by clicking directly in the image and you can fine tune a curve point by using the scroll wheel on your mouse.
The left image is straight out of the camera. The right image has been corrected in Capture One with the Curve Tool and the Color Editor.
To enhance this image, I first used the Color Editor to boost the colors a bit, but I found that the rocks in the foreground needed more contrast.
If I use the contrast slider in the Exposure Tool to add contrast to the rocks in the foreground, they just get darker. The built-in contrast correction adds contrast to the image – but not in the way I prefer for this image.
In the Curve Tool, I can see the location of a tone represented by a vertical line underneath the curve. Moving the cursor around on top of the rocks in the foreground, I can see that the first spike in the histogram originates from these rocks. In order to add contrast for these rocks, I start by adding a curve point by simply clicking on one of the rocks with the “Pick Curve Point” cursor tool.
To increase the contrast, I add another curve point. This time, I just click on the curve a little below the first curve point. I can drag this point with the mouse, but it can be done with much more precision by using the scroll wheel of the mouse. Place the cursor beside the last added curve point, and you will see that a horizontal orange control line appears. If I turn the scroll wheel, I can move this curve point up and down very precisely. To add contrast, I need to bring the curve point down turning the curve into an “S” curve shape. The maximum steepness of the curve, which creates the contrast effect, occurs exactly where it is needed to give contrast to the rocks.
Curve points can also be adjusted horizontally. To do this, I place the cursor vertically over a curve point and a vertical orange adjustments line appears.