The Curve tool.
The Curve tool in Capture One Pro is unique for two reasons, the Luma Curve and the floating option. Being able to size up to fullscreen the Curve tool is a valuable feature. We can work in a more precise way. But what is the Luma Curve ?
The Curve tool, in the combined RGB mode, allows us to change the tonal distribution of an image, but it is linked to the saturation. Sometimes this behavior is handy, sometimes not. So Capture One Pro proposes the Luma mode, which allows us to change the tonal distribution too but without being linked to the saturation, as you can see on the two images above. In principle, it works like changing the tonal distribution on the L channel of a Lab Curve tool or on the RGB Curve tool in Luminosity blend mode, in Photoshop (although the maths are not the same).
So, we have two modes in one tool so precise and powerful that I use it to replace the Contrast and Brightness sliders in the Exposure tool. Why ?
Because Brightness is equivalent to work on Curve, in the combined RGB mode, with one additional point and Contrast, same but with two additional points.
However, in the Curve tool, we can place these points where we want, working with them in a symmetric or an asymmetric way and choose to use them in the combined RGB mode, linked to the saturation, or in the Luma mode, not linked to.
Moreover, we have to understand something important. Contrast adjustments on a curve is represented by the slope. When we work with one additional point, as the left image, we are not only adding density to our image, we are creating two different contrasts because of two different new slopes. From 0 to 128 input value, we remove contrast. From 128 to 255, we add contrast.
When someone says we add contrast with a S curve is not exact. As the center image, from 0 to 64 and from 192 to 255, we remove contrast ! We add contrast only from 64 to 192 input value. Why is it so important ?
Because, since the combined RGB mode is linked to the saturation, we can use this behavior to work with curve as almost a SAT vs LUM curve. How ? As you can see on the right image, globally we are not changing a lot the density of our image because the curve is turning around the median line. But by gently playing with these three points, we are creating four different new slopes, and so four different saturation changes ! From 0 to 32, we remove saturation. From 32 to 64, we add saturation. From 64 to 128, we remove saturation. And from 128 to 255, we have the original saturation.
I use the Curve tool by combining a curve in the RGB mode to work my saturation by tonal range and one in the Luma mode to work my densities and contrasts by tonal range. One powerful and precise tool ! My experience says that the work on saturation by tonal range makes magic on every image and probably even more on X Series.
The Color Editor and its Uniformity options.
There are three modes in the Color Editor tool, Basic, Advanced and Skin Tone. The Basic mode can be skipped for the Advanced one. The Advanced mode is for me the most important tool in Capture One Pro. And the Skin Tone mode. Why this name ? Because historically it has been used a lot for skins. But its principle can be used on everything (and humbly I would like Phase One to change the name) !
How does this mode work ? As in Advanced mode, we first select hue and saturation values in our image and then we can shift their hue, saturation and Lightness values inside Amount (but in more subtle way than in Advanced mode). Inside Uniformity, we can go further. We can compress the values of our selection to an absolute hue value, represented by a point inside our selection, an absolute saturation value, represented by the left slider and an absolute lightness value, represented by the right slider.
On the right image above, we selected the hues from green to blue and the saturations from 100% to approximately 20%. And we asked to compress all the hues selected to an absolute value of 199, a blue/green, all the saturations selected to an absolute value of 46 and the lightness of all colors selected to an absolute value of 41. The result is precise and impressive, what makes this tool so unique !
So when we understand the principle of the Uniformity options, we can use them on everything, since we can create multiple Color Editor in Skin Tone mode with different layers.
