Sony recently introduced a unique solution for its latest generation of NEX models: The LA-EA2 adapter not only allows you to use legacy Sony and Minolta Maxxum lenses with the newest NEX cameras, but also incorporates a phase-detection AF system based on Sony’s Translucent Mirror Technology providing faster autofocus for both still and video recording.
For many years, the two most popular types of digital cameras have been compact models and digital SLRs. Each offers advantages over the other. Compacts are small (many will actually fit in a pocket), simple and self-contained. DSLRs, on the other hand, typically produce much better image quality (due to their larger image sensors), are much quicker, accept a wide range of interchangeable lenses and have convenient eye-level, through-the-lens optical viewfinders.
Over the last couple of years, a new type of digital camera has arrived on the scene, and quickly gained popularity: the mirrorless interchangeable-lens camera. In fact, in 2011, more mirrorless models were introduced than DSLRs. Mirrorless models combine compact size with DSLR image quality, thanks (in most cases) to putting a DSLR sensor into a compact body.
A popular (but not unanimous) complaint about single-lens-reflex cameras is that they’re too bulky. Back in the early 1970s, Olympus stunned the camera industry by introducing the OM-1, a 35mm SLR that was noticeably smaller than any that had come before. So it was not unprecedented that when a consortium introduced the compact Four Thirds System in 2003, the first Four Thirds model was an Olympus: the pro-oriented E-1 DSLR.
By designing DSLRs around a smaller 17.3×13.0mm sensor (most DSLRs of the era used "APS-C" sensors, which measure around 23.6×15.8mm), the Four Thirds System creators were able to produce smaller cameras, with smaller lenses optimized for the sensors. But most Four Thirds System models were not noticeably smaller than APS-C DSLRs (largely because of their bulky SLR mirror/prism viewfinder assemblies).
In 2007, Sigma introduced the DP1, a compact camera with a DSLR sensor—the same unique Foveon X3 unit used in its DSLRs. The DP1 was a truly compact camera that produced true DSLR image quality. However, it had a fixed 28mm (35mm-camera-equivalent) lens, which limited the user to wide-angle photography. The DP2 model that followed had a built-in 41mm (35mm-equivalent) "normal" lens. These cameras are still in production, in DP1x and DP2x form.
In the same year, the Four Thirds consortium introduced the Micro Four Thirds System. Based on the same 17.3×13.0mm image sensor as the full Four Thirds System, the Micro Four Thirds models reduced camera size by doing away with the DSLR’s bulky mirror box and pentaprism or pentamirror viewfinder assembly and replacing it with an eye-level electronic viewfinder. The first Micro Four Thirds camera was the Panasonic G1, which looked like a miniature DSLR and was noticeably smaller than the APS-C (and Four Thirds System) DSLRs.