Color (7.53)
Sony included 7.1 effective megapixels on its large 1/1.8-inch CCD and coupled it with a Real Imaging Processor. The image processor is the device that takes the data from the CCD and constructs it into an image file. Some image processors are more accurate than others at depicting actual colors. To determine how accurate the Sony W7's colors are, we took several exposures of the GretagMacbeth color chart and uploaded them into Imatest Imaging Software. The program analyzed the data and output several charts for comparison's sake. Below is a modified GretagMacbeth color chart with the ideal color in the inner rectangle. The outer square is the color produced by the Cyber-shot W7 and the inner square is the color-corrected version you would see when you uploaded the pictures into a software application.

Another chart is shown below to illustrate exactly how far or how close the W7's colors are to the ideal. The squares on the chart represent the ideal colors of the industry standard GretagMacbeth color chart. The circles depict the colors produced by the Sony W7. The greater the distance between the two, the less accurate that particular tone is.

The Sony Cyber-shot DSC-W7 performed decently with an overall color score of 7.53. This is very similar to the Sony W1, which scored a 7.51. Most of the colors in the W7 are slightly off the ideal, but the red #15 is especially exaggerated. This particular color is over-exaggerated in many compact digital cameras to enhance skin tones and conceal facial blemishes. Most compact cameras also slightly over-saturate the colors to make the scene appear more vibrant and pleasing to some; the W7 also does this, as it has a 104 percent mean saturation score.

Still Life Scene
Below is a shot of our inspired still life scene photographed with the Sony Cyber-shot DSC-W7.

Click on the above image to view a full resolution version (CAUTION: the linked file is very large!)

Resolution / Sharpness (5.87)
The W7 aims to be a contender in the major megapixel market with its 7.41 total and 7.2 effective megapixels on the 1/1.8-inch CCD. To test the number of pixels this camera actually uses, we took several un-cropped pictures of the ISO 12233 resolution chart and uploaded them into Imatest Imaging Software, which counted the pixels in each picture. If a camera comes within 70 percent of its advertised megapixel count, we consider that "good." When within 80 percent, it is "very good." We designate a camera as "excellent" when it comes within 90 percent, but this is quite rare.

Click on the chart to view the full res image

Recording 5.87 megapixels, the Sony Cyber-shot DSC-W7 recorded the most for a compact digital camera that we've tested (and also advertises near the top, I might add). This is still 83 percent of the advertised 3072 x 2304 pixel size that the best picture resolution offers, earning it a "very good" designation. The Sony W1, with its lower pixel count, recorded 84 percent of its advertised count.

Noise - Auto ISO (8.88)
We tested the noise levels while using the automatic ISO setting and found that the Sony W7 performed very well. It earned an overall automatic ISO noise score of 8.88, which is far better than the W1's score of 5.13. Most compact cameras score even below this, so the W7 is definitely on the better end of the cameras we've tested.

Noise - Manual ISO (8.09)
The Sony W7 offers a limited range of ISO settings: 100, 200 and 400. We tested the noise level at each of these settings and input the data into a regression analysis to determine the overall score. The noise level at each setting can be seen on the vertical axis on the graph below, with the ISO rating shown on the horizontal axis.

This Cyber-shot earned a slightly lower overall score when compared to its automatic noise score, which is odd. Most cameras perform better when manually adjusted, but this discrepancy is largely attributed to the lack of ISO options offered. The W7 received an overall manual ISO noise score of 8.09, which is still very good. For comparison's sake, the Sony W1 scored 8.28 in this same test.

Low Light (5.5)
To evaluate a camera's low light performance, we record four exposures of our GretagMacbeth color chart at decreasing light levels and import the images into Imatest Imaging Software. The software helps us perceive the degree of error in the camera’s reproduced colors as well as the volume of noise emitted at a specific light increment. The images are recorded at the camera’s highest ISO rating - ISO 400 for the W7 and shot using the Program exposure mode. If custom white balance is offered, we calibrate the camera at each differing light setup; however, when this is not applicable, as with the W7, we use the automatic white balance setting.

Cameras are tested at four diminishing light levels: 60, 30, 15, and 5 Lux. These levels are selected as a means of representation — simulating common low light conditions; 60 Lux appears to the eye as the soft cast of a bedroom might look after dark, when illuminated with two small lamps. When this is cut in half, down to 30 Lux, the emitted light equates to roughly a single 40 watt lightbulb. When dropped down to 15 and 5 Lux, the test displays the camera’s ability to record in near darkness and will isolate the limitations of the sensor.

Low Light Tests 60 Lux 30 Lux 15 Lux 5 Lux

As you can see from the above progression, the major low light issue with the DSC-W7 is color. Surprisingly, given the camera’s difficulty with automatic focusing, the W7 is able to maintain focus in diminishing light, even at 5 Lux. This is a common flaw of many compact cameras that remarkably, the W7 manages to avoid. However, the 7-plus megapixel W7 did not fare quite as well in terms of tonal representation in the compromised lighting setups.

In all of the low light scenarios, the W7 handled noise reasonably well, boosting the exposure without filling the images with grain. Even at 5 Lux, the chart is easily visible and the boundaries between tones clearly distinguishable. But the main point of contention is the camera’s horrid color calibration. Throughout the test (60 Lux down to 5 Lux), the exposures are tainted with glaring red overtones. The camera seems to be reading white as a dark blue, and shifting the tones accordingly. Without a custom white balance setting, images captured with the Sony W7 in low light will not be able to avoid this tonal deficiency and unless the user is partial to extremely warm casts, the images will require substantial work in an external software application.

Speed / Timing
Start-up to First Shot (8.7)
A few weeks ago, the Fujifilm FinePix F10 held our title for the fastest startup time in a compact digital camera we had tested--but we have a new winner. The Sony Cyber-shot DSC-W7 narrowly beats it out by 0.04 seconds with a 1.3-second time to its first shot.

Shot to Shot Speed (9.33)
There are two burst modes on the W7: burst and multi-burst. The burst mode is what most photographers will use. It takes sets of five pictures (at the highest resolution), with a long 19-second nap in between bursts. Those five pictures shoot as fast as 0.4 seconds, but average is around 0.67 seconds. There is also a multi-burst mode that takes 16 shots in 0.32 seconds. Don't get too excited though; it can only do this in a 320 x 240 resolution.

Shutter to Shot Time (8.76)
There is a tiny bit of shutter lag, as the camera takes 0.12 seconds to capture a picture after the shutter release button is pressed.