What is difference between tonal contrast and just contrast? Usually the editor programs will have a contrast slider while the "special" plugins of these software will have tonal contrast. Is tonal contrast basically a boosted contrast?
Sounds like just marketing to me. Contrast of course affects tone.– ItaiJun 17, 2013 at 2:44
Perhaps a little more than that, Nik's tonal contrast has sliders that effect shadows, mid-tones, and highlights so it's a bit more targeted than the global slider in ACR.– Joanne CJun 17, 2013 at 10:47
In my experience, "tonal" contrast is usually limited to a specific tonal range. Most tools that I have used that have a tonal contrast slider usually have something along the lines of "highlight tonal contrast" and "shadow tonal contrast". Tonal contrast is similar to global contrast in the way it behaves, simply with the added connotation that it affects an attenuated range of tones, rather than all tones.
I am not sure what a single "tonal" contrast slider might mean, it wouldn't make sense to me to have a "contrast" slider and a "tonal contrast" slider that did not affect a restricted range of tones. If your software only has a "tonal" contrast slider it might be a local contrast setting.
It should be noted that global and tonal contrast is (or should be) a little different than "clarity", "local contrast", or "microcontrast", which is a setting that affects all tones, however in a "local" or "relative" context...relative to neighboring content, rather than on a global scale. Local contrast is much more subtle at lower settings, and much more impactful at higher settings, than global contrast.
If tonal contrast is contrast applied to a specific tonal range, how is it different than curves/levels? With those tools you are also adjusting contrast at a specific range?– erotsppaJun 17, 2013 at 18:23
1It's another view into the same basic manipulation that Curves does, but may be easier to use.– mattdmJun 17, 2013 at 18:42
Matt pretty much nailed it...just a simpler tool. Curves can achieve the same thing for sure, but curves can also do a hell of a lot more, and in each color channel independently. Curves are really an advanced tool, where as a tonal contrast slider is just another basic setting that you can tweak with ease. For all intents and purposes, Lightroom's monochrome "Tone Curve" IS "Tonal Contrast". Difference is it can be switched to full RGB point curve editing as well, which makes it a much more powerful tool than simply "tonal contrast".– jristaJun 17, 2013 at 18:57
As I understand it, "tonal contrast" is used to distinguish from other types of contrast — in a technical sense, that might mean microcontrast (which is edge sharpness) — but in a larger sense it might mean as opposed to contrasting color or other elements of the composition which may contrast, like the size, shape, or pattern of subjects of the photograph.
Usually in photo editing and manipulation software, contrast means tonal contrast. It seems likely the plugins are just being extra precise. Certain filters my use the term to help imply that they work on the contrast within certain ranges of tones (shadow contrast, for example), but that's not really inherent to the meaning.