Case solved! Movie theaters generally have red seats because of this...

When watching a movie, have you ever noticed the color of the cinema chairs? Many cinema seats are red, and this color is not chosen randomly. The red seats are actually to reduce interference and enhance our viewing experience.

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Red is not just a tradition

There is a saying that the reason why the seats in the cinema are red is because it follows the color of the theater seats in ancient times. In the early days, theater seats were mainly used by royal aristocrats, who liked the gorgeous red color, so the color of the seats in the cinema followed this tradition.

Neatly arranged red chairs in the theater. Copyright image. Reproduction may cause copyright disputes.

But this inevitably raises questions. Cinemas are no longer for the royal aristocracy, and the public's aesthetic tastes are becoming more and more diverse. Why aren't cinema seats colorful?

To understand this, we must first talk about the visual cells in the human eye .

There are two types of cells in the human eye that are responsible for sensing light: cones and rods.

Cones are divided into three types, which are most sensitive to blue-violet light, green light, and red-yellow light respectively. They work together to form our color vision.

The sensitivity of the three types of cones to different colors of light. Image source: Wikipedia

However, cones can only function better in conditions of sufficient light, so they are mainly responsible for bright vision.

There is only one type of rod cell, and they have little to do with color vision, but because rod cells are more sensitive to light, they are mainly responsible for dark vision, helping us see clearly at night and in very dim places.

The two systems of light and dark vision in the human eye cause differences in our sensitivity to colors under light of different intensities.

Purkinje effect

In 1825, Czech anatomist Jan Evangelista Purkyně published an article documenting his observations on light and dark vision.

He found that at dawn, before the sun rises, the light is very dim, and people see mainly black and white, especially red, which is particularly dim in low light. As the sun rises slowly and the brightness increases, people will first distinguish blue, then green, and finally red.

Purkinje speculated that as the light gets weaker, the human eye's sensitivity to red will decrease faster. In other words, in dim light, the human eye is least sensitive to red. This phenomenon was later called the Purkinje effect .

Simulating the human eye's ability to recognize red under different brightness conditions. Image source: Wikipedia

In later studies, scientists also confirmed that in dim light, cones are very insensitive to red, especially deep red.

From top to bottom, the sensitivity of bee vision, human photopic vision, human scotopic vision, and human pure rod cell vision to different wavelengths of light. Image source: Reference 2

Red seats don't interfere with your vision

When a movie is playing in a cinema, most of the lights are turned off. In this case, the screen is the brightest light source, and the brightness of the light is enough for the cones to work, so that we can see a variety of colors clearly.

In contrast, the area where the seats are located is almost pitch black, and the weak light reflected by the seat backs will hardly attract the attention of cones, while rods may be able to sense these weak lights. At this time, the color of the seat backs is crucial.

Visible light spectrum, Image source: Wikipedia

If the back of the seat is red, the rod cells are not sensitive to red light, so such a seat will not easily attract our attention and will not affect the viewing experience.

On the other hand, if the chair back is green (wavelength is around 500nm), the rod cells are very sensitive to light in this wavelength band, and the outline of the chair back may always appear in our field of vision, thus affecting the viewing experience.

Of course, both cones and rods are not very sensitive to dark purple and black in dim light, so theoretically these two colors can also be used as "candidate colors" for movie theater seats. But you can imagine that it would be quite strange if the backs of the seats in the movie theater were all black or dark purple.

Therefore, most movie theaters use red or dark red seats. Even if there are other colors, they are rarely bright yellow or bright green.

The eye-catching "little green man"

However, when watching a movie, if the content of the movie is boring, you may be attracted by the emergency exit sign next to the screen.

The reason why it is so conspicuous is, of course, that they are bright in themselves, and also because of their color. In the "Fire Safety Signs Part 1: Signs" (GB13495.1-2015), it is also stipulated that the signs used to prompt emergency evacuation and escape need to use green as the background color.

Image source: Reference 3

The reason for using this color is to enable people to identify escape signs more quickly in the thick smoke of a fire.

At the same time, green is the complementary color of red, so such signs can be more conspicuous in the red flames, which is helpful for life-saving and escape.

Therefore, red seats and green safety signs in movie theaters have almost become the "standard configuration". But if the content of a movie is not as attractive as the sign of the emergency exit, perhaps it is not a good movie.

References

[1] Silver P H. A Purkinje shift in the spectral sensitivity of gray squirrels[J]. The Journal of Physiology, 1966, 186(2): 439-450.

[2] Land MF, Osorio D C. Color vision: coloring the dark[J]. Current Biology, 2003, 13(3): R83-R85.

[3] Fire Safety Signs Part 1: Signs (GB13495.1-2015)

Planning and production

Author: Xiaowei Popular Science Creator

Reviewer: Tao Ning, Associate Researcher, Institute of Biophysics, Chinese Academy of Sciences

Planning丨Wang Mengru

Editor: Wang Mengru

Proofread by Xu Lailinlin