An in-depth, jargon-free guide to the pros and cons of this pioneering system The Four Thirds system is an innovative, open standard for digital SLR cameras that is designed to optimize their size, performance, compatibility, and extendibility. Standardization of lens mounts enables photographers to mix and match interchangeable lenses and camera bodies from different makers. Because lenses traditionally optimized for film cameras don't always perform well with the digital camera's image sensor (the device that captures light in the form of electrical signals) the Four Thirds system,...