Here are some of my first photos with the NEX 5. If you can see the aperture (all 2.8 I think), then it is with the kit 16mm lens.
If photos are not of a gingerbread house, and aperture shows f1, then it is with the Canon 28/2.8 lens at 2.8 (with R/J M to NEX adapter).
If photos are of a gingerbread house, and aperture shows f1, then the lens is a Sweeney modified J3 @ 1.5, with addl. shims to focus between about 18" and 20 feet (about 1mm extra shims between LTM adapter and lens).