Lock on Barbwire -- NEX-5 & Kodak Cine 102mm f2.7. Click to see larger.
Due to the larger sensor on the NEX cameras, most c-mount cine lenses can not cover sensor area, and consequently, pictures would have a dark boarder. There are only few cine lenses that work on NEX-5 without severe vignetting. Most of them are long lenses, including these ones that I have tried: Kern 50mm f1.4, JML 50mm f0.95, Kern 75mm f1.9, Angenieux 75mm f2.5, Fuji 75mm f1.8, Birns & Saywer 150mm f3, Kinoptik Speciale Cine 210mm f2.8. All wide angles that I have tried vignette to a certain degree. Most Kodak cine lenses vignette very badly. This really disappoints me, because I love Kodak cine lenses. They are underrated and supremely sharp and nice lenses. The only other sad thing about the Kodak lenses is the focusing stiffness. The grease dried up and they all need to be re-lubed to focus properly.
If you are looking for a cine lens for your NEX, before to find out if it vignettes, unless you like that effect.