Contrast controls in LR2

[stroberaver]

I routinely run my photos through Lightrom, and in fact rarely call up Photoshop unless I need to specifically edit or manipulate it in some way that Lightroom can't.

However in Lightroom's Develop module, there is a "basic" section and a "tone curve" section. At the bottom of the tone curve is the option to set the curve to presets of linear/low/med/high contrast, while in the basic section there is a slider for contrast.

What's the difference between these two controls? I understand what the tone curve control does, but don't know whether the contrast slider is another way of controlling this? Or does the slider manipulate the image in some way unrelated to the tone curve controls?

Thanks in advance.

[David Kilpatrick]

The tone curve is editable and takes an inverse-S form to increase contrast while crushing black and rolling off highlights. The contrast control clips black and clips highlights, it just alters the angle of the line or curve being used for the photo globally.

David

[stroberaver]

Thanks David. I suspected something along those lines based on my tinkerings with images yesterday, but nice to know for certain.

[UrsaMajor]

The tone curve is editable and takes an inverse-S form to increase contrast while crushing black and rolling off highlights. The contrast control clips black and clips highlights, it just alters the angle of the line or curve being used for the photo globally.
David

Just to pick a nit, I think that you inadvertently defined this backwards. I believe that an "S" shape to the tone curve would do what you describe. I think that an "inverse-S" shape to the tone curve would reduce contrast, open up the shadows, etc.

With best wishes,
- Tom -

[David Kilpatrick]

It's an S as you view it but in sensitometric terms, an inverse S - just to be difficult. I used to call it an S-curve but found myself corrected because the terminology is still based on negative processing.

David