On last week’s RetouchPro Live session, I talked about adding atmospheric effects to photos in a realistic way. The key point I kept trying to drive home was of paying attention to the details in the image you’re manipulating. While this is probably a good rule-of-thumb for all photomanipulation, in atmospheric effects it has a deeper impact.
This is because atmosphere is heavily dependent on the actual image itself. Everything about the scene has the potential to contribute to atmospheric effects – dust, haze, fog, rain, etc. And not all of it will be in obvious ways. Much of what happens is in very subtle cues that human perception has come to rely on. Look at aerial perspective: the effect of air on a scene as that scene takes in more and more physical distance. Objects that are far off are seen through more air than objects that are close. On Earth, that air is typically filled with dust and moisture, and tends towards blue due to absorption of light. The amount and combination of those constituent parts makes up how we perceive something that is far away.
Let’s take the example of a mountain range. If you shoot it from fairly close, you may see some blue cast to the shadow areas, but may not notice anything in the highlights or mid tones. But backing away, not only are the details less distinct, the color begins to shift. A desert scene will take on less color cast with distance because there is less moisture. When you go to composite elements in a desert image versus one in an alpine image, you need to consider the amount of water and dust in the air, and how it affects the perception of distance. In fact, some distant desert scenes may actually be neutral or warm because of the dust in the air. What this means is you have to pay attention not only to the distance you want to portray, you have to pay attention to the content as well.
The best way to get a feel for how atmosphere affects an image is to go look up some photos. Use your favorite search engine and use keywords like ‘fog’, ‘dust’, ‘haze’, etc. These will return a wealth of reference photos you can use to get an idea of what you want to get across. And as you look at the samples, ask yourself what you are seeing that makes the image real.
In upcoming blog entries, I’ll break down some of the individual effects you can achieve, and how to coax them into photorealism starting with nothing but Photoshop’s native filters.