Sony DSC-T20 Optics

Zoom
Good performance with the 3x optically stabilized zoom lens. Digital zoom also performs fairly well.

The Sony Cyber-shot DSC-T20's optical zoom covers the equivalent of 38-114mm, which is a typical focal range for an ultra-compact lens. Overall performance is good, with good detail and sharpness at both wide angle and telephoto, although there is noticeable chromatic aberration and some softness in the corners. The camera's 2x digital zoom also performs pretty well, with better results than we usually associate with digital zoom, although still not nearly as sharp or detailed as optical zoom.

Macro
A below average macro area in Standard Macro mode, but with excellent detail and high resolution. Flash exposure was uneven and overexposed. A very tiny area in Super Macro mode, but with excessive corner softness and loss of detail.

The Sony DSC-T20's standard macro setting is below average, capturing a fairly large minimum area of 2.83 x 2.13 inches (72 x 54 millimeters), but detail and resolution are both excellent, with little softening in the corners. Super Macro mode captures a tiny area of only 0.63 x 0.47 inches (20 x 16 millimeters), however corner softness extends deep into the frame. (Most cameras have some softening in the corners in macro mode.) The flash is uneven and has a bit of trouble throttling down, blowing out most of the exposure, so plan on using external lighting for the best results with the DSC-T20's macro settings.

Distortion
Moderate barrel distortion, high pincushion.

The Sony Cyber-shot DSC-T20's 0.7% barrel distortion at wide angle is about average among the cameras we've tested, and noticeable in some of its images. At the telephoto end, the DSC-T20's pincushion distortion is much higher than average at about 0.5%, and is quite noticeable in some images. 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).

Chromatic aberration
Significant at wide angle, with noticeable effect on images at edges.

Chromatic aberration is moderately high at wide angle, showing about 5-6 pixels of bright coloration on either side of the target lines. At full telephoto, chromatic aberration is lower, and not as bright. Overall, the effect is noticeable in a few of our wide angle test shots. Note: 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
Slight blurring in the corners of the frame at wide angle and telephoto.

The Sony Cyber-shot DSC-T20 produces slightly soft results in the lower corners of the frame at full wide angle, while the upper corners are pretty sharp. At full telephoto, there's also slight blurring in the all corners of the frame, but with very little effect on resulting images. This is a good performance overall.

Coverage
Good accuracy from the LCD monitor. The DSC-T20 does not have an optical viewfinder.

The Sony Cyber-shot DSC-T20's LCD monitor shows about 102% coverage at wide angle, and about 101% accurate at telephoto. In both cases, the image is shifted vertically somewhat.