This subforum defines native lenses as "lenses designed specifically for Micro Four Thirds." But in practice, some of us define it more broadly. Take the Sigma 19, 30, and 60mm primes. They were designed for the larger NEX. But in M43 mount, they provide full electronic coupling: autofocusing, full-aperture metering, and EXIF data. Are they native? They're certainly native enough. Inversely, the manual-focus Samyang/Rokinon/Bauer/Bell & Howell 7.5mm fisheye was designed exclusively for M43. But it can't communicate with the camera body. You won't get full-aperture metering, or EXIF data. Technically, the Samyang fisheye is an M43 native lens. But in practice, it hasn't fully "gone native". Then there are the curiosities in the middle: a handful of older Sigma autofocus lenses designed for full-frame but offered in M43 mount, complete with electronic coupling. Not native glass, by any stretch. But arguably more M43-friendly than the manual-focus Samyang fisheye. Finally, there are the original four-thirds lenses. They can't be called native, because to use such a lens on an M43 body, you need an adapter. But not on the new EM-1. A Tokina lens for APS-C in Nikon mount is considered a Nikon-native lens, even though the same lens is offered in Canon mount. So clearly, a lens need not be offered for one mount exclusively. In fact, even if a third-party lens focuses "the wrong way" (e.g., couterclockwise=farther focus), it's considered native when it's offered in that mount. I'm inclined to say that a lens is native to Micro Four Thirds if it electronically couples without an adapter. By this measure, i would say that the Samyang fisheye is not a true native lens...perhaps quasi-native.