Sony NEX owners don't exactly have a ton of lenses to choose from. There are many adapters out there for Leica, Nikon, Canon and other lens brands. But the latest from Metabones includes features that truly change the lens-adapter game.
It's called Speed Booster, and it comes on Metabone's latest-generation Canon EF to Sony E-mount adapter. What Speed Booster does is preserve the focal length of full-frame lenses on APS-C cameras like the Sony NEX series. See, since forever, shooters with APS-C size sensors in their cameras have been seeing longer focal lengths than what is inscribed on their lenses. A 50mm lens turns out to be 80mm (if the crop factor is 1.6x), a 24mm lens turns out to be roughly 38mm, and so on. Your field of view shrinks because the sensor is smaller.
But with Metabones Speed Booster, the image is focused onto a smaller area, and the entire field of view is preserved as if you were using a full-frame camera. AND THAT'S NOT ALL.
Because the image is focused smaller, the light passing through becomes intensified, and that means your lens will receive about 1 stop of extra brightness. Like magic, your f/1.8 lens becomes an f/1.2 lens.
Skeptical? Initial reports by likes of Philip Bloom and Andrew Reid at EOSHD show promising results with prototype tests. The adapter with Speed Booster is available for pre-order for Sony E-mount and Fuji X-mount. It will run you a cool $600. Not cheap, but the benefits are clear. [Metabones via EOSHD]