Special Effects

Although Emile Cohl brought stop-motion over to America in 1908, it wasn't until much later that the animation technique became more well known to the public. And this was mainly down to one man - Willis O'Brien. 
An ex-newspaper cartoonist, he had been hired by the Edison Company in the mid-1910s to make short films on prehistoric subjects, and in 1925 had worked on his first feature The Lost World. Known for his talent of animating creatures for special effects, he managed to get a job working for King Kong in 1933. This film was extremely innovative for it's time, although it may not seem it nowadays. For the film, O'Brien integrated the stop motion sequences with live action footage.

Another influential person in stop motion, was O'Brien's protégé Ray Harryhausen. Having been hired by O'Brien to work on the 1949 Mighty Joe Young, he stepped out of the shadow of his master and is now known as a household name in stop motion. Harryhausen perfected many of the techniques that O'Brien had originated, including trying to integrate the animation into the fabric of the film as seamlessly as possible. He created DynaMation, which split the live action footage into the foreground AND background shots, so that he could "sandwich" his own work into the very centre of the film. This forward thinking way of working finally won him the Gordon E. Sawyer Award from the Academy of Motion Picture Arts and Sciences for his technological contributions in 1991.

After this, stop motion became more and more inventive, and more and more seamless. So now we have entire stop motion animated feature length films, that you wouldn't know were made in this painstaking way.