There are a few different ways to control where in your image the viewer looks first. There’s Color, Brightness, Shape, and Contrast. I’d like to talk for a minute about Contrast, since it’s my favorite way to control where the viewer’s eye goes in a picture.
Look at the two pictures below. They’re the same shot, but each one is processed differently (the contrast manipulations are exaggerated for demonstration purposes).
Now, the first image is clearly about the couple. The eye is immediately drawn to them, and they almost seem to emerge out from the picture…. the rest of the image is just a background to them.
In the second image, the building is the main subject. the couple has become just a foreground element to the geometric intricacies of the building.
I processed this image by lowering the global contrast in lightroom to almost nothing, and then created an adjustment area with the radial filter which boosted the contrast in a small area back up to the regular level. In the first image I made the radial filter area small and positioned it over the couple. In the second image I made the filter area large and positioned it over the hotel.
So what can be learned from this technique? Well, first, the eye is drawn to areas of high contrast. Bright white tones next to Dark shadow areas is like crack to our retinas.
Secondly, you can notice that the low-contrast areas have a very soft look to them, and seem to almost be further away than they are. There’s a reason for this misperception, and that reason is atmospheric effects on light.
See, when you look at something a few feet in front of you, there’s not a lot of air in between your eye and that object. However, if you’re looking at that same object at a distance of a half mile or so, suddenly there’s tons of air that you’re peering through. And that air, even on a clear day, will — you guessed it — lower the perceived contrast of the object you’re looking at.
You see this all the time. Think of the last time you looked at a mountain range. The closer mountains had a higher degree of contrast than the further away ones. Really far away mountains almost always have a sort of a hazy look to them, because of all that air you’re looking through.
So by controlling the amount of local contrast on parts of your image, you can actually make things look like they’re closer or further away from the camera, softer or harder, and you can easily shift the focus of your image around. It’s a powerful way to control the viewer’s eye, and if it’s done subtly is almost subconscious in execution. Got a distracting element in the back of your picture? Lower the contrast on it! Problem solved!