Sony Cyber-shot DSC-W7 review

Performance
One of the Sony Cyber-shot DSC-W7's biggest attractions and the main improvement from the DSC-W1 is its speed. Thanks to a fast processor, this is a quick little camera from the moment you turn it on. It takes just 2 seconds from the time you push the power button to the time the camera is ready to take its first shot, an interval that bests many cameras costing much more. Autofocus time and shutter lag are very short for its class, at an average of 0.3 second under high-contrast conditions and 0.5 second for low contrast. Typical time between shots is just 1.4 seconds, or 3.6 seconds with flash using the bundled 2,100mAh rechargable nickel-metal-hydride batteries. Continuous-shooting performance is only average at 1.3fps for 5 shots, but at 7.2 megapixels per image, that's not bad. Knock the resolution down to 640x480 pixels, and you can shoot at about that speed for 100 straight frames.

Image review is also very fast; holding down the scroll button will let you fly through 30 7-megapixel, low-compression images in just more than 4 seconds. The zoom lens slides in and out fairly quickly and quietly, too.

Shooting speed
(Shorter bars indicate better performance)

Typical shot-to-shot time

Time to first shot

Shutter lag (typical)

Sony Cyber-shot DSC-W7

1.4

2

0.3

Olympus Camedia C-7070 Wide Zoom

2

3.9

0.5

Sony Cyber-shot DSC-V3

1.5

3.7

0.5

Canon PowerShot G6

2

3.1

0.8

Pentax Optio 750Z

3.9

5.6

1.2

Continuous-shooting speed
(Longer bars indicate better performance)

Minimum

Maximum

Sony Cyber-shot DSC-W7

1.3

1.3

Olympus Camedia C-7070 Wide Zoom

1.6

2.1

Sony Cyber-shot DSC-V3

1.0

2.8

Canon PowerShot G6

0.8

1.7

Pentax Optio 750Z

1.0

1.3

Image quality
The Sony Cyber-shot DSC-W7's image quality is excellent for its class; while there are some flaws, especially at the corners of its image, they are very minor and noticeable only under close scrutiny. Blooming -- the leakage of bright backlight onto dark objects such as branches against a sky -- is very tightly under control and barely visible. Chromatic aberration, or the purple fringing often seen around high-contrast objects, is also negligible. The lens is fairly sharp in the centre, rendering details well, and a calibrated monitor reveals dynamic range and tonal separation to be very good as well. Barrel distortion, which makes images look curved outward at the edges at wide angles, and pincushion distortion, which has the opposite effect at telephoto angles, are both very minor.

The DSC-W7's lens doesn't do as well when it comes to the edges of the frame, where discriminating eyes will notice vignetting and a falloff in focus. The latter is especially apparent on the left side of scenes. Using the automatic multipoint focus ensures that more areas of your photos are sharp, but the camera doesn't always choose the same subject as you would. Photos taken at ISO 100 show relatively low noise, and pictures taken at ISO 200 look almost the same. Some sensor noise is visible at ISO 400, but this Sony performs better in this regard than many other cameras in its class. Some JPEG compression artefacts, such as jagged or smeared edges and white or dark halos at high-contrast edges, are visible in many images shot with low compression.

The camera's automatic exposure system, especially with multipattern metering, is very accurate even in tricky backlit situations. The flash will occasionally be too powerful, but if that's not corrected by metering on something lighter, then you can turn down the flash power.

The camera tends to oversaturate a scene's colours a little too much but only very slightly and nowhere near as much as other offenders in the consumer arena. Controls are provided to lower (or increase) saturation and contrast to taste. The automatic white balance works very well in sunny and cloudy outdoor conditions, but setting the camera to its tungsten preset yields more accurate colours when in the presence of incandescent lighting. The camera's fluorescent white-balance preset works well under certain types of fluorescent lights, but under some, colours are rendered too reddish; you're better off using the automatic white balance.

Edited by Lori Grunin
Additional editing by Tom Espiner