Early animation featured moving characters on static backgrounds. The character was drawn on celluloid sheets and placed on top of background art, each frame of the character’s movement matched by a tiny shift of the backing scenery to give the impression of the character inhabiting the space. This tactic rendered the character wonderfully, but presented challenges in creating lifelike backgrounds.

As the overlaid character moved in and out of a physical space, the background perspective didn’t change naturally. Scenery also fell victim to unrealistic point of views if the camera zoomed in or out on a subject. Instead of the viewer’s perspective honing in naturally, everything would blow up. As Walt Disney explained in a 1957 recording, with traditional animation practices, if the camera zooms in on a picture of a farm at night, the moon gets bigger. In reality, walking closer through a farmland doesn’t amplify the size of the moon—it should always be the same size in a night sky.

Walt Disney’s team tackled this problem by inventing the multiplane camera, a device capable of shooting several images at once to render a complete animation. The process involves moving a number of pieces of artwork past the camera at various speeds and at various distances from one another. Though not truly stereoscopic, the result creates something that appears three-dimensional. The setup can also make the background and foreground move in opposite directions, creating a spinning effect.

Snow White and the Seven Dwarfs (1937) was the first film to employ the use of a multiplane camera. Walt Disney commissioned the camera’s creation for the film as he felt it was necessary to ramp up the imaginative nature of animation if people were expected to sit through a feature-length cartoon. Snow White was the first such picture, after all. Audiences were used to watching cartoons as five-minute preludes to a main feature, not as the feature itself. The film was Disney’s attempt to prove that animation was a viable means of telling a complete narrative, so it was important to come up with something dazzling. The camera shot through layers of oil-based images on pieces of glass, allowing for more sophisticated manipulation of the images than ever before.

The multiplane camera allowed the background to give the impression of movement beyond simply side-scrolling, as was the standard at the time. It also made possible new types of special effects, such as the movements of water, and the flickering of the stars or light. Walt Disney filled the cels in Snow White with a richness of detail not present in previous cartoons. That artistry, combined with the new filming technology, made for an animated picture unlike anything anyone had seen. Not only were the scenes filled with more robust imagery than people were used to, but the animations moved in unprecedented ways. The multiplane camera also allowed for greater directorial possibilities as the setting and characters could be manipulated in a more lifelike fashion, offering a more immersive experience.

As Ebert wrote, “Snow White demonstrated how animation could release a movie from its trap of space and time; how gravity, dimension, physical limitations and the rules of movement itself could be transcended by the imaginations of the animators. Consider another early example, when Snow White is singing ‘I’m Wishing’ while looking down into the well. Disney gives her an audience—a dove that flutters away in momentary fright, and then returns to hear the rest of the song. Then the point of view shifts dramatically, and we are looking straight up at Snow White from beneath the shimmering surface of the water in the well. The drawing is as easy to achieve as any other, but where did the imagination come from, to supply that point of view?”

As such, Snow White is revered as a technological marvel that changed animation for decades. It would already have been immortalized as the first full-length animated feature, but its advances in the field have given its legacy a twofold importance.

The multiplane camera would be the means of animating Disney features all the way through The Little Mermaid in 1989, at which time it became obsolete. A “digital multiplane camera” was then invented, the first step in transitioning animated films from hand-drawn art to the computer-aided creations we almost always see today.