Fujifilm X-S1 Digital Camera Review$799.95
We measured notable chromatic aberration throughout the X-S1's focal range. Most of the the time, it's visible only in areas of very high contrast, like the edges of buildings against a gray sky. For such a versatile lens, that's okay.
At the telephoto setting, chromatic aberrations skyrocket—up to five times the camera's average. It's plainly visible in our resolution crops—fringing is obvious and ugly in every case, and really drags down the full-zoom image quality to the point where we'd consider avoiding the maximum focal length at all. Backing off a bit helps, though.
Basically, the X-S1 suffers from more chromatic aberration than the typical camera even without the poor telephoto performance, probably due to its ambitious lens. In most cases, it shouldn't be enough to bother most photographers with reasonable expectations for a camera like this, but everyone will notice that it's problematic at the longest focal length.
A zoom lens with a relatively wide starting point always suffers from distortion, but the X-S1 adjusts for the effect. We measured just 0.78 percent barrel distortion at the wide angle and a virtually unnoticeable 0.14 percent and 0.22 percent pincushion effect at the middle and telephoto settings, respectively. The results are so good that we didn't penalize the X-S1 at all; it earns full points in this category (as do at least half of all cameras that we test). RAW images are more distorted, but that's expected.