A New Standard Designed Specifically for Digital SLR

The new Four Thirds System achieves the best image quality possible by maximising the performance of two core elements; the image sensor and lens to create an all new camera system for digital photography.

Moreover, this new format makes it possible to design cameras and lenses that are much smaller than their 35mm counterparts, giving professionals anytime anywhere mobility. And, because the Four Thirds System is an open standard, it holds great promise for system expandability.

As film can be exposed by light coming from oblique angles, most 35mm film camera lenses are not designed to ensure that light only strikes the film from straight ahead. Conversely, the image sensor used in a digital camera is a chip with pixels laid out at regular intervals on a grid, with photodiodes in the depressions inside the pixels.

As a result, light can only reach the photodiodes effectively if it comes straight through the lens. This means that if a 35mm film camera lens is attached to a digital camera, colour reproduction tends to be inaccurate and brightness insufficient at the periphery of the image sensor where light is apt to strike obliquely.

The Four Thirds System solves this problem by ensuring that light is passed through to the image sensor in a straight line, thereby achieving consistently high image quality even at image edges and even when wide-angle lenses are used.

Smaller, Brighter Lens Expands Shooting Possibilities

Lenses for digital cameras should be designed so that light is accurately captured not only at the centre of the image, but also on its periphery. Passing light straight through to a 35mm- equivalent image sensor would require lenses so large they would be unusable.

However, with the Four Thirds System, the diameter of the lens mount is much larger than that of the image circle, making it easy for light to pass straight to the image sensor. This not only makes the system compatible with various kinds of image sensors, it also greatly expands the flexibility of lens design.

Moreover, since the required focal length for the Four Thirds System is half that of a 35mm camera, it makes it possible for lenses to be much smaller than traditional 35mm camera lenses.

For example, with the Four Thirds System, a 300mm lens can achieve the same telephoto effect as a 600mm lens of a 35mm camera. In the near future, it will be possible to make much brighter lenses much shorter, dramatically expanding the creative possibilities of digital photography.