My uncle gave me my first real camera, an old 35mm Leica with a collapsible lens. It was lightweight, compact enough to fit into a pants pocket, and took great pictures. That camera, along with many other 35mm and medium-format film cameras, is now gathering dust in a drawer, pushed aside for a larger and heavier digital SLR.
When Panasonic and Olympus announced the new Micro Four Thirds camera system last August, their promise of smaller and lighter digital SLRs had me wondering if I would finally have a camera with the compact lightweight body of that old Leica in a digital format. Micro Four Thirds and the older Four Thirds systems are very interesting concepts, not simply because of what they promise but because the basic philosophy behind the systems runs so counter to traditional thinking about cameras.
Four Thirds -- better and smaller consumer cameras
The Four Thirds system was created by Kodak and Olympus in 2002; the first Four Thirds cameras hit the market in 2003. Currently, Olympus, Leica and Panasonic all have models available, while the lenses are made by Olympus, Leica and Sigma. The system is an open standard, which means any Four Thirds camera can accommodate any Four Thirds lens, no matter the manufacturer.
The Four Thirds system (and the later Micro Four Thirds system) takes its name from two ideas: the size of a camera's image sensor and its aspect ratio. Four Thirds casts off the 3:2 aspect ratio still used by consumer-level digital SLRs in favor of a more enlargement-friendly 4:3 ratio. High-end broadcast TV cameras use an image sensor with a diagonal measurement of 2/3 of an inch. The Four Thirds systems use an image sensor that is twice the size of a standard 2/3-inch TV camera sensor. Nothing about the Four Thirds image sensor actually measures 1 and 1/3 inches, but the idea that two 2/3-inch sensors put together equals a 4/3 sensor fits nicely with the 4:3 aspect ratio.
However, more importantly, the Four Thirds System uses an image sensor that is smaller than the APS-C-sized sensors commonly used in consumer digital SLRs and that's significantly smaller than a full-size 35mm sensor.
The inventors of the system wanted to create a smaller, lighter camera that would be easier for casual photographers to handle, and the Four Thirds System's smaller image sensor allows them to achieve that smaller design.
Now, the technology has gone a step further with Micro Four Thirds, which was announced last August. The Micro Four Thirds system replaces the bulky mirror-and-prism mechanism that makes up an SLR's viewfinder with an electronic one, allowing for even smaller and lighter designs. The system also has a slightly different lens design, which means Micro Four Thirds cameras can accept older Four Thirds lenses by using an adapter (although the newer format's lenses will not work on older cameras).
So far, one Micro Four Thirds camera has come on the market. The Panasonic Lumix DMC-G1 is quite a bit lighter than most traditional SLRs and slightly smaller as well. Bundled with a zoom lens, the DMC-G1 is debuting at a hefty US$800, although some stores are now selling the camera and lens for a much more competitive US$670.