Why Are Night Scenes Blue?

You’ve either seen it on one of those posts that point out some of the ridiculous “things we’ve learned from movies” or maybe you’ve even noticed it yourself. But right there along with always finding a parking spot in front of the courthouse and every tank you shoot with a bullet is highly explosive, you’ll discover that everything at night is perfectly visible, but slightly blue. What’s up with that?

Well, the first thing is, it has to be visible. As I mentioned in a previous post, film is a method of preserving light. No light? No movie magic. Blue helps indicate that something different is going on, mainly the passage of time. It’s one of those subtle things that Hollywood hopes you pick up on, but don’t really notice. But why blue?

Color Temperature

If you’ve been shopping for lightbulbs recently, you’ve probably seen this little diagram.

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That’s right. Lights are different colors. Chances are, you’ve never even noticed this before. Your brain has a habit of calibrating to subtle differences. That’s why you don’t go insane with all of the noise in a city and you stop noticing the tint on your rose colored glasses after a while.

A Look At The World Through Rose-colored Glasses.

But if you pay attention, you’ll start to see nauseating scenes like this.

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Filmmakers put a lot of effort into making sure this kind of catastrophe never appears on the big screen.

The thing is, you really only notice the different colors on their own. If the entire wall were orange or blue or green, the lights would have that distinct hue, but your brain would tune it out. It’s the comparison that makes it noticeable. What color is the sun? Well, it looks pretty blue when you compare it to a campfire.

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Moonlight, after all, is just reflected sunlight. I don’t know about you, but I’d say that night scene is pretty blue looking.

The other major source of light we’ve had as humans has been the incandescent lightbulb, which also glows at a warm orange 3200K*.

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Photo by Vitaly Vlasov on Pexels.com

So why color temperature?

There’s a bit of physics involved here, but the basic idea is that if you heat something to a particular temperature without it bursting into flames, it will start glowing. So an incandescent bulb (which glows because it’s being heating) is, in fact, pretty close to a temperature of 3200K.

Daylight is measured between 5500K and 6500K. The sun’s light is diffused by the atmosphere, so it’s a little bit of a moving target. But the actual surface temperature of the sun? 5778K. Not too shabby.

Fluorescent lights and LEDs  do not use heat to produce light, but are still measured on the same scale.

More Science

Human eyes detect light with two different kinds of cells: rods and cones. Rods simply detect light, not color. Cones are sensitive to particular wavelengths of light and separate out small (blue), medium (green), and long (red). The other colors are made by blending wavelengths. At low light levels, only your rods will activate and the world will be a series of shadows and silhouettes. But as more light is introduced, the small cones may be activated, and you’ll start to see a little bit of blue first.

So don’t feel blue the next time you’re riding off into the moonlight, even if everything may look it.

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*Color temperature is measure in Kelvin (K), named after Lord Kelvin who created the absolute temperature scale. Since 0K is so cold molecules would stop moving, it’s also called absolute zero. (Yes, Andre 3000, that’s cooler than being cool.) Also, Kelvin is just Kelvin, not degrees Kelvin.

Lights, Camera, Action (Part 2)

Psychology of Lighting

Like all aspects of filmmaking, lighting has subtle, psychological effects on the audience. Knowing what these effects are and knowing how and when to use them will greatly enhance any film you make.

Low Key*: Darkly lit or low light scenes evoke a sense of mystery and danger, like this shot from The Shape of Water. 

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High Key: Brightly lit scenes like the opening of La La Land tend to be happier.

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Soft Light: Few or poorly defined shadows create a sense of fantasy. For example, I find dragons and armies of undead more realistic than the fantasy world created in Letters to Juliet.

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Hard Light & High Contrast: Well defined shadows create a grittier look like Sin City.

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Warm Colors: Orange hues can evoke warm feelings and romance.

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Cool Colors: Blue is used to create a sense of cold or uncaring.

Limitless Blue
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The previous two images are both from the movie Limitless. You’ll notice the color difference the most by looking at Bradley Cooper’s skin tone. Skin tone one of the first reference points audiences latch onto.

Other colors can be used to create a sense of unease, like something isn’t right. The Matrix, for example, was decidedly green.

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Knowing the Toolkit: Skilled cinematographers, of course, can also use these techniques ironically or to create a new meaning with juxtaposition. One example is flash photography.

Flash Photo

You get this effect by having a harsh, bright light source right next to the camera (as you would on a disposable camera or smartphone). Things close to the camera (like faces) get washed out, while the background is underexposed. It also creates harsh shadows. (Look at the distinct black line on the left side of the red coat). It looks amateurish. But if you want your project to look like it was made by amateurs, this is your ticket. Thank you, Blair Witch Project.

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One Final Thought

When you think about it, all movies, all TV shows, all video games, every viral video you watch on your phone is really a manipulation of light on a screen. The realty – the screen – remains unchanged. The meaning comes from your mind’s interpretation of that light and the story it creates. Controlling that light is the difference between staring at static and touching an audience.

 

*The “key” in “low key” and “high key” refers to the “key light” or main light source.

Lights, Camera, Action! (Part 1)

What is it with films and lighting? It’s right there, number 1 in the most cliched of all Hollywood phrases*. And if you’ve ever been on a film set, you know that the vast majority of time is spent lighting and relighting the scene. But why?

Visual Medium

At its basic level, film (and the modern equivalent of digital video) is actually a way of recording and preserving light. So while we think of films as epic stories with huge budgets and special effects, it’s really a specific kind of recording device. On a technical level, you could compare film to taking a plaster impression of an animal print or recording tremors with a seismograph.

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Photo by Luriko Yamaguchi on Pexels.com

For those of you old enough to remember developing photos from 35mm film, this is “film” at its most basic. Photons bounce off an object, are focused by a lens onto the film, activate photo-reactive chemicals, and leave an impression. The film is then developed into a negative, and the negative is used to produce the positive picture.

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The thing is, that 35 mm film from your disposable CVS camera is actually the same film used in movie cameras and was essentially unchanged for 100 years. Today, the process is digital, but essentially your iPhone and a professional movie camera work the same way. And it’s all about capturing light. 

What are we waiting on?

So why does it take so long to light a film set? There’s a problem between seeing and seeing. Your brain plays probably about the same role in sight as your eyes. Yes, your eyes perceive light, but your brain needs to decide what to focus on (literally and figuratively). In addition to actual focal distance, it must determine proportion, patterns, colors, shapes, and movement. Are you looking at a cat or a lion? Or a toy lion? Or a picture of a lion? 

Our brains concentrate on only one small part of what we actually see. But when a filmmaker sits you in a darkened room and projects an image 30 feet tall and 100 feet wide, they need to direct your attention. They have to be sure what they are showing you is more interesting than the exit sign in the corner of the theater or that weird haircut on the guy two rows in front of you.

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Just to be clear, your director of photography and the camera are taking the place of the two most complex organs in the human body. This involves framing shots appropriately, dressing and costuming appropriately, and making sure the correct subject matter is in focus. And it also involves a LOT of lighting. 

Consider this shot from Citizen Kane.

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It’s both simple and incredibly effective. The main sources of light come from the back of the room, creating a hard silhouette of both subjects. They are both easy to see while also being obscured. The light beams add a sense of depth, while the desk lamp fills in some of the void. That way we aren’t merely looking at silhouettes.

This shot required critical placement of the lights, camera, and actors. The lights had to be focused and balanced in intensity so the desk wasn’t too dark or the beams too bright. Smoke or fog played a critical role in creating those beams, too.

Physics of Photography

Whether you’re taking photos at a wedding or shooting a film for Spielberg, everyone’s playing by the same rules. Light and film have certain properties and limitations. A lot of cinematography is understanding these limitations and finding a way to get the look you want with the tools you have.

Concentrate! 

There can be a lot of stuff in a scene: actors, props, sets. How does your audience know where to look? Light, of course. Here’s a very messy photo from my office.

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Now where did I leave that fine point black Sharpie? When I change the lighting, it’s a little easier to see. sharpie

Exposure

Ever had an annoying camper shine a flashlight in your eyes in the middle of the night? First, it’s painfully bright. Then it takes your eyes a few seconds to readjust to the darkness. Your irises make minor adjustments constantly, and because it happens so fast, you don’t usually notice. What happens if you’re filming a scene that includes very bright and very dark parts?

Here, Phillies Bear and Phanatic Pillow Pet are very excited to watch the Phillies (currently number 1 in the NL East!), but the problem is, the window behind them is grossly overexposed.

Philly overexposed

If we set the exposure for outside, it looks like they are sitting in a black hole.

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The solution is to add light inside the room or take light away outside (most likely by putting filters on the windows). Either way, it’s going to involve some lighting.

Inverse Square

The intensity of lights decreases as you get further away. Not by a little, but by a LOT. In fact, light follows the inverse square law. That means if you double the distance between your subject and your light source, but want to keep the same light intensity, you need to quadruple your lighting power. Bigger shot? More lights.

How many lights did it take to illuminate this post-apocalyptic set from Bladerunner: 2049?

 

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Well, start counting.

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You’re out of your depth. 

Lighting adds a sense of depth to a scene. After all, we see in three dimensions, but movie screens are flat. If there were no depth, everything would look like a cartoon. In the shot from Bladerunner: 2049, you can see the silhouette in the foreground, our actor in the middle distance, and hazy ruins in the background.

This shot from The Third Man, shows the depth of a tunnel. Even as a still frame, you get a sense of the dimension.

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Check out this image source for a great post about depth with lighting

Today, many movies are shot in 3D, but lighting still plays a critical role in creating the space for a scene.

Next Time…

That covers some of the technical hurdles that go into lighting a scene. In the next post, I’ll cover some of the other things a director of photography considers on a set.

 

*The phrase “lights, camera, action” was probably never used to get a film crew rolling. Even today, lights take a while to warm up. There is also some dispute about the origin of the phrase. In reality, the dialogue before a take goes something like this:

1st Assistant Director: “Let’s roll.”

Production Assistants: “ROLLING!”

Sound department: “Sound speeds.”

2nd Assistant Cameraman: “101 take 1. A mark.” (Hits slate.)

Camera Operator: “Set.”

1st Assistant Director: “And… Action.”