Developed jointly by Olympus and Panasonic, the Micro Four Thirds system was the first true mirrorless interchangeable lens camera system available.
The imaging sensor has an aspect ratio of 4:3, unlike many other cameras that stick to the same 3:2 aspect ratio of 35mm film. There's also a crop factor of 2x, which means a 25mm lens is required to provide the same angle of view of a 50mm lens used on a 35mm camera.
Currently, Micro Four Thirds camera owners have the widest range of lenses to choose from, with lenses from both manufacturers being compatible with all Micro Four Thirds cameras. Due to the wide support this system enjoys, third-party lens and accessory manufacturers such as Sigma and Voigtlander also supply compatible products. Adaptors for a wide range of lenses are available to enable them to be mounted on Micro Four Thirds cameras.
Spec: 16MP, 1080p video, 3-inch adjustable touchscreen, EVF
Featuring a newly designed 16MP digital sensor and Venus Engine VII FHD processor, Panasonic promises that the G5 delivers images that are cleaner and freer of noise than seen before on a G series camera. Panasonic is keen to call the G5 a Digital Single Lens Mirrorless (DSLM) camera, since it's slightly bigger than most CSCs.
Innovative new features such as the TouchPad AF operation and Eye Sensor AF are appealing. It also has a good number of automatic controls, digital filters and scene guides to appeal to novices or those looking simply to point and shoot.
The Panasonic G5 is our Best mid-range CSC award-winner.
Read our Panasonic G5 review
Spec: 12.1MP, 1080p video, 3-inch touchscreen
Panasonic has done a great job at building a compact system camera that will appeal very strongly to those looking to step up from compact or bridge models, while keeping enough manual controls to satisfy those looking for more.
The amount of detail the Panasonic Lumix GF5 captures is particularly impressive - especially considering the lens we used for the majority of our shots was the supplied kit lens (albeit the more expensive option). This is a great option for those looking to get started with a compact system camera.
The Panasonic Lumix GF5 wins our Best entry-level CSC award.
Read our Panasonic GF5 review
Spec: 16MP, 1080p video, 3-inch LCD touchscreen, extensive manual control
Aimed at enthusiasts and experienced photographers, the Panasonic Lumix GX1 sports plenty of manual control options in a compact, rugged metal body. Adjustments can be made via the camera's physical controls or via the 3-inch touchscreen interface.
A resolution of 16MP enables large high-quality prints to be produced, and video can be recorded at 1080p in the popular AVCHD format. Support for SD, SDHC and SDXC cards is also included, providing plenty of storage options.
Although no optical viewfinder is included, an accessory port on the rear enables an electronic viewfinder to be attached with relative ease. Other stand-out features include a maximum continuous shooting speed of 5.5 frames per second (fps) and an electronic level, which will help to ensure your images don't suffer from wonky horizons and leaning buildings.
Read our Panasonic GX1 review
Spec: 16MP, 1080p video, 3-inch swivel LCD touchscreen, built-in EVF
The Panasonic Lumix G3 squeezes advanced controls, an electronic viewfinder (EVF) and a 3-inch swivel touchscreen interface into a svelte lightweight body with DSLR styling.
20fps continuous shooting is possible at a reduced resolution of 4MP, and a not too shabby rate of 4fps at full resolution, making this camera suitable for capturing fast-moving action.
Generally well received at its launch, the Panasonic Lumix G3 also produces high resolution 16MP images, suitable for reproduction at large sizes, and 1080p video recording in the popular AVCHD format.
Read our Panasonic G3 review
Spec: 16.05MP 17.3x13mm Live MOS sensor, Full HD video, 3-inch 614,000-dot variangle touchscreen
Panasonic has made the GH3 more appealing to serious photographers than the Panasonic GH2 by increasing the number of direct controls it has on its body and giving it a more robust magnesium alloy construction that is dust and weatherproof.
The GH3 is also quite a bit bigger than the GH2 that it replaces and it is a similar size to an entry-level SLR.
As on the GH2, the GH3's 3-inch screen is touch-sensitive, but it's a capacitive device and very responsive, so it makes selecting settings, making adjustments and scrolling through images very easy.
The GH3 produces high quality still images and movie footage, but as is often the case, we recommend keeping the sensitivity below ISO 6400 where possible.
All the modern conveniences that we want from a digital compact system camera are provided by the GH3; a decent EVF, an articulating capacitive touchscreen, Wi-Fi connectivity and a fast autofocus system. Not to mention excellent image quality.
Read our Panasonic GH3 review