Talking Pixels

Adobe Lightroom has several ways of tweaking a picture to improve it’s look.  I’m going to compare two methods in this post.  For illustrative purposes, I’ll use the below image for the basis of comparison.

The first is ‘Contrast’.  Nothing new here as contrast adjustments have been around since the beginning of digital editing.  Increasing contrast makes everything to the left of middle gray darker, and everything to the right of middle gray lighter.  It’s a good, general use tool, but the effect is global, and often yields areas of the image that lose detail because they are either too dark or too light.  Here’s the original image with the contrast bumped to 100%.

What do we notice?  Well, we can see that the mid tones are similar to before.  Not much has changed there.  The ends of the gradients are dramatically different though.  Take a look at the thin vertical white bars in the top gradient.  There are 10 of them, but you can hardly tell that the bar to the far left is there any more.  Also notice that the black vertical bars of the lower gradient seem to be missing a few on the left side.

On to ‘Clarify’.  I seem to remember that this came out a few revisions ago, so it’s fairly new.  I read one Lightroom reviewer call it the ‘make it look better’ slider (referring to the fact that the control is a slider with a range of -100 to 100).  Clarify takes a different approach to increasing contrast as if focuses it’s efforts towards the tones in the middle of the histogram.  Let’s take a look at the example first.

As you can see, the middle zone of these gradients were really effected by the Clarify tool.  So what happened here?  Edges between contrast differences were enhanced to increase their perceived local contrast.  Let’s take the top gradient as our example.  The gray area surrounding each white vertical bar was darkened.  This effectively made the white vertical bars appear to be brighter, or at least, stand out more.  They didn’t really change, only the gray area around them changed.  If you look at the lower gradient, you can see that the gray area surrounding each dark vertical bar was lightened, effectively lowering their perceived darkness.  Also notice that the effect reduced as you go out from the center of the gradient, towards the lighter or darker ends.

What does this all mean?  It means that you have two tools for different types of images.  Contrast is an excellent tool for images that, one the whole, are flat.  Flat images are defined as those that are heavily loaded with middle tones, and don’t have significant dark or light areas.  These types of images would benefit from the global effect that Contrast imparts.  Clarify, on the other hand, would be better suited for an image that needs a little extra boost in the middle tones, but not in the extreme dark or light areas.  A good example of this type of image would be a relatively well exposed landscape image that has sufficiently dark shadows and good highlight detail, but detail in distant mountains is lacking due to haze.  This haze would fall in a middle tone, and by increasing Clarify, you could help bring out some details that were one lacking.

In practice, I rarely use Contrast to actually adjust the contrast of an image.  I would be more inclined to use a curves adjustment as I find that I have a little more control over where the contrast is applied.  If I do use it though, I rarely add more than about +20.  Clarify on the other hand, can stand a heavier hand.  So when I use that, I often use values around +20 to +40.

I hope you found this comparison of Contrast and Clarify useful.

Geoff