Both visually and by the numbers, the NEX-5 delivers excellent noise performance for its class. Photos are pretty clean up through ISO 800, and you don't start to see significant softness until ISO 1,600.
Sony has really gotten its act together on the noise-reduction algorithms; these are some of the best high-ISO-sensitivity images I've seen from a Sony camera, even the dSLRs.
(1/50 sec, f4.5, evaluative metering, AWB, standard Creative Style, 18-55mm lens at 42mm)
Though the HHT photos look a little softer than their straight high-ISO equivalents (the EXIF data reports this at ISO 1,250), you can see how clean this looks. Still, HHT takes too long to shoot and record the photo to use it for anything but static scenes; good performance at high ISO sensitivities is not obsolete.
At its widest angle, the 18-55mm kit lens displays some of the worst barrel distortion we've seen for a nonsnapshot camera in a while. Goodbye, straight lines. (1/100, f9, ISO 200, spot metering, AWB, Standard Creative Style)
As you'd expect from a prime, the distortion characteristics are much better than the kit zoom. It looks pretty good, actually, although I think there's a bit of vignetting in the lower left corner. (Note 5/19/10: it turns out that Sony shipped out preproduction 16mm lenses, so it's possible the slight vignetting is a nonissue. I'll retest when I receive the production unit. Settings: 1/100, f10, ISO 200, spot metering, AWB, Standard Creative Style)
Bokeh, or the quality of out-of-focus details, makes a big difference in lens quality. Though the lens has a 7-blade aperture, I was surprised at how polygonal some of the out-of-focus highlights looked. (1/800, f8, ISO 200, spot metering, AWB, Standard Creative Style)
A combination of the default Creative Style, with its unknown adjustments and an overly cool automatic white balance in sunlight, unfortunately shifts deep pinks, greens and purples. Still, if you don't care about accuracy, the colors are mostly pleasing and saturated.
This remains a fun feature, though not without its bugs. The detail level is a lot better than from the point-and-shoot models (right), but it still has a problem dealing with things moving through the scene (left). Thank you random stranger in the park. (16mm lens)
In a change from previous versions, the NEX-5's Auto HDR implementation saves an un-blended version of the image as well as the 3-shot-combined one. The Auto HDR version is lower contrast and a bit softer, but as you can see extracts a lot of detail out of the highlights and shadows. (1/100 sec, f4.5, ISO 1600, evaluative metering, AWB, 18-55mm lens at 39mm)