Lighting: Atmospheric Perspective

The following analysis will look over what makes some of the most fundamental rules of cinematic lighting: depth and its root in atmospheric perspective. The rules include: depth through color, depth through value, short lighting, rebalancing contrast ratios, and rebalancing rim.

While contrast ratios are paramount to cinematic lighting, this post will not delve too deep into it, but a deeper discussion can be found in the previous post HERE.

Depth through Color

The most apparent aspect of atmospheric perspective is color separation: objects closer to you appear to be warmer, but the same object placed farther away would appear cooler in temperature because it’s affected by more atmosphere. This is one of the easiest ways we can tell what is close or far over a distance. This effect can be compressed into scenes to give shots within a room or small space the same feeling of depth.

Examples from High School Musical 3 and Hotel for Dogs:

The lighting doesn’t even have to be fully motivated. In Inglourious Basterds examples below, the bar scene sells depth with shafts of moonlight coming into the basement.

Depth Through Value

Now, onto the most important rule of atmospheric perspective that makes the biggest difference in film: value.

John Alton’s quote on depth in his book, Painting with Light:

“At night when we look into an illuminated room from the dark outside, we can see inside but cannot be seen ourselves. A similar situation exists in the motion picture theatre during a performance. We sit in the dark looking at a light screen; this gives a definite feeling of depth. In order to continue this depth on the screen, the progression from dark to light must be followed up. The spot which should appear to be the most distant should be the lightest, and vice versa”

Alton’s depth theory is similar to how we naturally perceive depth with atmosphere. In short, the closer an object is to the camera, the darker and low key (high contrast) it must be in value, and the farther an object is, the brighter the more high key (low contrast) it is in value. 

These Hotel for Dogs show the brightest pings in the BG with a darker FG to maintain value depth :

Short Lighting

As a continuation of the previous rule of having darker objects in the foreground and lighter objects in the background, we can tie in the concept of short lighting. Short lighting is key lighting from the “inside” of the subject’s face. This limits the amount of light coming from the camera’s direction onto the front of the subject, thus keeping the foreground dark and the short side of the subject brighter. If the subject is broadly lit, the image is flatter and depth is lost.

Short lighting also applies to non human subjects like landscapes, buildings and planets

Rebalancing Contrast Ratios

The next two rules are about breaking lighting continuity to maintain atmospheric perspective through rebalancing (relighting for each camera setup).

John Alton’s rebalancing quote in Painting with Light:

“When a long shot was made, instead of moving in on a close-up and relighting they merely switched lenses. The result was a flat, overlit, and usually disastrous close-up. This can easily be explained. In a long shot the face of an actor may be only a small part of the picture. Sometimes, to suit the balance of the lighting scheme, the scene is overlit. When we change lenses, we eliminate everything but the face, and all we get is a flat white surface. Fortunately, this practice is slowly becoming outmoded. To get quality, every close-up or portrait should be lit separately and balanced individually.”

In film, the DP can maintain high contrast lighting of objects in the FG and low contrast in the BG for every camera setup (so you always change lighting based on where an object is in Z-space). This might seem like an unnatural way to light setups, but it is actually related to the natural phenomenon, atmospheric perspective. For atmospheric perspective, if you were outside and walking forward in z-space, a plane in space that was once far away and light in value would be darker and higher in contrast when you are closer to it.

Casablanca:

Rebalancing Rim

The last technique of maintaining depth for each camera setup involves keeping bright values out of the FG to maintain atmospheric perspective – and the brightest light in each shot is usually the rim light. Essentially, this rule is to always keep the rim light a rim light, even if you move the camera. This is the biggest instance of “cheating” light logic, but you’d be surprised how this is ubiquitous in film, TV, and commercials that achieve the “cinematic” look. This might look odd as stills and because I’ve called attention to it, but the majority of viewers will not notice because the motivation/source of the light remains constant.

In High School Musical 3 and Hotel for Dogs shots below, notice how rim is removed or moved for characters in both scenes in reverse shots to maintain atmospheric perspective:

The rim can also be moved more elastically like the Sun in The Incredibles: