The key difference is that instead of focusing the light on a strip of photochemical film as in traditional cameras, digital cameras use an image sensor, called a charge coupled device (CCD), to capture the image.
The new model has also been real-world tested and proven by Contour's roster of professional athletes and film partners in the world's most diverse conditions, ultimately fine-tuning its sensor to improve the overall sharpness of the image, the speed at which the camera adjusts for fast lighting changes, and the underwater video quality.
In addition, you can now use Monochrome or Film Simulation modes when video recording and even take advantage of the X-E1's large sensor and bright XF lenses to capture movies with beautiful bokeh effect.
Just as grain size in silver halide film ultimately limits the amount of detail you can see in a photograph, the background noise produced by the sensor does much the same in digital imaging.