Lightroom’s Clarity Slider – What Does It Do?

With the introduction of version 1.1, Lightroom has had a slider titled “Clarity”. In the beginning the slider went from zero to one hundred. Now, in version 3.3, the slider has a range from -100 to +100. I often use the slider for my photo work and am happy with the results.  Helen has mentioned it a number of times in her tutorials here on DPS as well, but what is it that the Clarity slider is doing to my pictures?

Initially confounding me in my quest for an answer was the fact that it didn’t always have a sizable effect on all images. Some images had drastic changes and some had very little. Why? After doing some research on the web and in the histogram, I came to learn that the Clarity slider is mainly affecting the mid-tones. And it is affecting them by adding contrast, usually without much added noise. This can be handy for a number of reasons, but like any widget in a photo program, can be over used.

I’m going to show a couple of before and after examples to highlight which photos will gain value from the Clarity slider use.

First is a shot of a wave crashing against the Australian shore. (Pixel peepers can get a 2000 pixel wide view of all pictures by clicking on them)

This is the image with zero Clarity adjustment.  Knowing that the Clarity slider creates contrast in the mid-tones, I can look at the histogram and know this image will have a fairly large adjustment.  Now I’ll show you back to back versions of +100 and -100 on the Clarity slider (NOTE: I am using +100 and -100 to show the dramatic effect the slider can have. Rarely would I use either setting in reality.)

There is a fairly dramatic change between images.  Because the wave and rock detail are in the mid-tones, it is helped and hindered greatly by the use of the slider.  Notice also that the highlights, like the sky, change very little.  Now I’m going to check out the effect when an image is more towards both ends of the histogram.

This photo is of Ed Bennett, proud proprietor and head brewmaster at the Boundary Bay Brewery and Bistro in Bellingham, Washington, USA (they like their B’s up there).  Taking a look at the histogram, while there are mid-tones present, they is a lull in the center, the area most effected by the Clarity slider.  Now to take a look at the +100 and -100 examples.  How much effect do you think it will have?

Again, the blownout sky is left to its own devices.  The darks in Ed’s shirt and parts of the building openings are also left alone.  His face is tightened up a little as there are mid-tones present, as well as the edges of the buildings, plus the sign.  All in all, not a huge change because there wasn’t as much in the center of the histogram.   Lastly I’ll show an example of where the Clarity slider is almost useless and I hope you’ll be able to tell me why even before seeing the two examples of +100 and -100.  First, the original.

This marshmallow roasting scene, on the beach at Semiahmoo Resort in Blaine, Washington, USA, has the histogram pushed to the edges.  What will the effect be from the Clarity slider?

The biggest change is to the few mid-tones found in the flames and in the sky.  Because of the silhouettes and other dark elements, this image does not receive a strong treatment.  Although, I want to note, I do somewhat enjoy the watercolor effect of dropping the Clarity to -100 that is represented in the sky.  Certainly it takes the image out of a standard, representative photograph, yet it imparts an interesting feel that doesn’t work with the photo of Ed.

To sum up, the Clarity slider adjusts the contrast in just the mid-tones.  This is a handy feature to have as it will not add grain to the highlights or shadow area as an all purpose contrast adjust will.  It is a useful tool for most photos, just be careful of overusing it, as it can produce very harsh edges that are unrealistic when printed.