Various Forms of Contrast in ACR

Hi All,

I'm a little perplexed at how the best way to go about adjusting contrast in Adobe Camera RAW is.

There is the Contrast slider
There is the Curves dialogue
There is the Clarity slider

I'll tell you what I do know (or think I know) and what I usually do with each. If anyone could make any suggestions or fill in any missing or wrong information or give their perspective I would be wonderfully appreciative!

Contrast slider: I think this controls global contrast. I tend to stay away from it and leave it set to "0" because I've been a little brainwashed into thinking that contrast sliders are a cheap and dirty way to adjust contrast that Curves would do much better with. Which leads me to....

Curves dialogue: I usually apply a light to moderate S-Curve intially to every image before I start everything on the "Basic" panel with white balance, exposure etc. As far as I know I am applying global contrast to the image (possibly more accurate/powerful than the above method?)

Clarity slider: From what I know this affects only mid-tone contrast. I take this to mean that it controls the contrast outside of the shadows and highlights. I know this is used to give images "pop" but I'm not exactly sure why as compared to other methods.

I'll wrap it up now but just to steer you in the right direction, I tend to ask myself questions like, "Why would I touch the contrast slider if I can adjust the contrast more accurately with Curves?"

-Randy

The contrast slider is global contrast; however it basically adds mid tone contrast and consequently ends up reducing contrast in both the highlights and the shadows.

The curves adjustment allows you to make contrast adjustments to specific areas of the histogram while minimizing adjustments to other areas. You could mimic the contrast slider with curves if you wanted to.

I believe the clarity slider could be considered more of a micro-contrast or detail; however, I'm not 100% sure if this is an accurate description of the clarity slider.

I normaly use the contrast slider to add more contrast to my images and then use the curves to tweak the contrast a bit more depending on the image content.

RandMan wrote in post #15075361
Hi All,

I'm a little perplexed at how the best way to go about adjusting contrast in Adobe Camera RAW is.

There is the Contrast slider
There is the Curves dialogue
There is the Clarity slider

I'll tell you what I do know (or think I know) and what I usually do with each. If anyone could make any suggestions or fill in any missing or wrong information or give their perspective I would be wonderfully appreciative!

Contrast slider: I think this controls global contrast. I tend to stay away from it and leave it set to "0" because I've been a little brainwashed into thinking that contrast sliders are a cheap and dirty way to adjust contrast that Curves would do much better with. Which leads me to....

Curves dialogue: I usually apply a light to moderate S-Curve intially to every image before I start everything on the "Basic" panel with white balance, exposure etc. As far as I know I am applying global contrast to the image (possibly more accurate/powerful than the above method?)

Clarity slider: From what I know this affects only mid-tone contrast. I take this to mean that it controls the contrast outside of the shadows and highlights. I know this is used to give images "pop" but I'm not exactly sure why as compared to other methods.

I'll wrap it up now but just to steer you in the right direction, I tend to ask myself questions like, "Why would I touch the contrast slider if I can adjust the contrast more accurately with Curves?"

-Randy

Are you using Lightroom 4? In these types of discussions its always useful to state what specific software you're discussing. And frankly if you are using LR4 your workflow needs rethinking. What if a specific image does not need as S-Curve? What if instead a reverse Z-curve or a "dog leg" work better? How would you know if you routinely and reflexively apply an S-Curve to every image?

The contrast slider is the global adjustment and should generally be used third; after white balancing and setting exposure. The Curves is a more specialized tool that allows you to target specific tones for adjustment, which is why it comes with a Targeted Adjustment Tool in the upper left corner of the panel. You can get a quite useable image by just setting the Contrast slider (either negative or positive) without touching either the Curves or Clarity slider.

Clarity is a local contrast adjustment; like the Curves panel it is a more specialized tool.

I suggest that you read The Digital Negative: Raw Image Processing in Lightroom, Camera Raw, and Photoshop by Jeff Schewe

I just use the contrast slider. KISS (keep it simple).

PixelMagic wrote in post #15075814
Are you using Lightroom 4? In these types of discussions its always useful to state what specific software you're discussing.

No, I'm using ACR/Adobe Camera RAW as I stated in the subject and first line of the post.

PixelMagic wrote in post #15075814
What if a specific image does not need as S-Curve? How would you know if you routinely and reflexively apply an S-Curve to every image?

I completely understand why you would ask this; 90% of my photos need a contrast boost when I load the RAW. I like to do it as my starting point because if I do the exposure and luminosity first in the Basic panel, after I add a Curve after it is often enough to clip highlights and/or shadows--then I have to go back to the Basic panel again and compensate. And if the image doesn't need an S-Curve, then I just don't use one (most of the portraits I have I do not end up using one).

PixelMagic wrote in post #15075814
Clarity is a local contrast adjustment; like the Curves panel it is a more specialized tool.

Specialized how? (if you happen to know)

RandMan wrote in post #15076253
No, I'm using ACR/Adobe Camera RAW as I stated in the subject and first line of the post.

Adobe Camera Raw and Lightroom have the same processing module so its a distinction without a difference.

Oh well, its your workflow and your images.

Rather than trying to reinvent the wheel; here's some dated but very useful information. Clarity is somewhat similar to a technique used in Photoshop called HIRALOAM (high radius, low amount) Unsharp masking to boost midtone contrast: http://www.luminous-landscape.com/forum/in​dex.php?topic=24097.0