Sony DSC-W55 Optics

Zoom
A typical 3x optical zoom range, with good performance.

The Sony Cyber-shot DSC-W55 zooms over the equivalent of a 38-114mm range, which is fairly typical for its class. Overall performance is quite good, with good detail and sharpness at wide angle. The 2x Precision Digital zoom takes it out to 6x total. As you'd expect, detail suffers with the digital zoom, but to our eyes, not quite as much as with some cameras.

Macro
A very small macro area, but severe blurring in the corners. The flash had trouble throttling down, and produced an uneven exposure.

The Sony Cyber-shot DSC-W55's macro setting captures a very tiny minimum area of only 0.97 x 0.72 inches (24.5 x 18.4 millimeters). While the macro area is quite small though, details are somewhat soft throughout the frame, with crisp definition only in the very center of the frame. Most cameras have some softening in the corners in macro mode (evidence of the optical characteristic "curvature of field"), but the W55's blurring extends quite far into the frame. Shooting at the minimum macro focal distance, the flash also had a hard time throttling down, and couldn't cover the frame evenly. (Plan on using external lighting for any macro shots with the DSC-W55.)

Distortion
Slightly lower than average barrel distortion, but high pincushion.

This is the tendency for the lens to bend straight lines outward (like a barrel--usually at wide angle) or inward (like a pincushion--usually at telephoto). The Sony DSC-W55's 0.6% barrel distortion at wide angle is a little less than average among the cameras we've tested, though still fairly noticeable in its images. At the telephoto end, the W55's 0.5% pincushion is higher than average.

Chromatic aberration
Moderate, small effect on images at edges.

Chromatic aberration is moderate at wide angle, showing about 5-6 pixels of fairly bright coloration on either side of the target lines, but decreases to very low levels at telephoto focal lengths, and in no case extends very far into the frame. - The chromatic aberration on the W55's lens was similar to what we saw with the W50. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.)

Corner Sharpness
Some softening in the corners of the frame at wide angle and telephoto. Better than average overall sharpness though.

The Sony DSC-W55 produced slightly soft corners in a few wide angle shots and telephoto shots.

Coverage
Optical viewfinder tight and skewed toward the top of the frame. Good accuracy from the LCD monitor.

The DSC-W55's optical viewfinder was quite tight, showing only about 80% of the final frame area at both wide angle and telephoto lens settings. However, the LCD monitor showed about 101% accuracy at wide angle and 99% at telephoto.