Color (5.22)
The Olympus Stylus 720SW uses a TruePic Turbo image processor which, according to the marketing materials, gives pictures “true-to-life colors.” We tested this claim by taking pictures of the GretagMacbeth color chart, which many imaging companies use to determine what colors should look like. The camera does not have a manual white balance mode, so we tested in the automatic and tungsten color balance modes in our studio setup, ultimately finding that the tungsten setting produced more accurate colors.
We uploaded the images to Imatest imaging software, which output the following modified color chart. The outer background edge of each tile shows the color that the 720SW recorded. Inside it is the corrected version which appears when pictures from the camera are uploaded to a computer. Finally, the inner vertical rectangle in each tile shows the ideal color from the original GretagMacbeth chart.
The following chart shows the same information as a graph. The squares represent the ideal colors; the circles represent those produced by the Olympus Stylus 720SW. The length of the lines shows how erroneous or true-to-life the colors are.
Photographers who fear off-color “digital-looking” photos should avoid the 720SW. It received a 5.22 overall color score, one of the worst ratings we’ve seen in awhile. Mean color error was 11.8, and the Olympus Stylus 720SW under-saturated colors by almost 5 percent. Even in its most accurate mode, the Stylus 720SW produced unrealistic color during testing.
Still Life Scene
Below is a shot of our still life scene, captured with the Olympus Stylus 720SW.
Click on the image above to view the full resolution version.
Resolution / Sharpness (3.88)
The Olympus Stylus 720SW advertises 7.1 effective megapixels of the 7.4 total on its 1/2.3-inch CCD. To test the camera resolution, we shot several pictures of the ISO 12233 resolution chart, which is widely used to standardize megapixel definition and detail. Test results are reported as line widths per picture height (lw/ph), a theoretical measurement of how many alternating black and white lines fit across the frame before blurring together. Scores came from the sharpest shots, those taken with an aperture of f/4.8 and a focal length of 18.3 mm.
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Horizontally, the Olympus Stylus 720SW read 1706 lw/ph and over-sharpened by a slight .0082 percent; vertically, the camera read 1737 lw/ph and over-sharpened by 3.06 percent. It performed comparably to the Canon PowerShot A620, which advertises 7.1 effective megapixels and returned a decent 1708 lw/ph horizontally and 1787 lw/ph vertically. The final resolution score for the Stylus 720SW was 3.88, fairly strong for a camera of this type.
Noise - Auto ISO (3.39)
The Olympus Stylus 720SW has an automatic ISO setting that its automatic-oriented audience will likely use often. We tested this setting for metering accuracy and noise. Under perfect lighting conditions, the Olympus Stylus 720SW didn’t have a metering problem; it automatically chose an ISO around 80. Unfortunately, this digital camera produces a lot of noise, even at the lower end of the ISO range. Thus, the Stylus 720SW achieved a lackluster 3.39 automatic ISO noise score.
Noise - Manual ISO (6.81)
More and more compact digital cameras are offering higher sensitivities this year to facilitate more natural looking low-light photography. The Olympus 720SW follows this trend, offering an 80 to 1600 ISO range. Many compact digital cameras, however, have noise with the higher sensitivities. To see if the Olympus Stylus 720SW displayed this phenomenon, we tested noise levels at each manual ISO setting. The chart below shows the results, with each ISO setting on the horizontal axis and the accompanying noise level on the vertical axis.
Noise levels start higher than those in comparable models, but the increase looks about the same. On this Stylus, noise steadily climbs from 80-400, then plateaus to 800, then jumps again to 1600, the highest ISO. While the lower end of the ISO range is noisy in comparison to other manufacturers’ lower ISOs, the 720SW’s overall score was saved by the plateau and relatively low noise at the higher end. When the noise score from each ISO setting was plugged into a regression analysis, the Olympus Stylus 720SW received a 6.81 overall manual ISO noise score.
Low Light Performance (4.75)
The Olympus Stylus 720SW seems poised to be a decent camera in low light. Olympus invested in a wide ISO range that brightens up to a high 1600 setting. The camera also has scene modes optimized for low light. For these low light tests, we used the night scene mode, which slowed the shutter speeds down more than other modes would on this Stylus, and took pictures at four different light levels. The first test was shot at 60 lux, which is about as much light as one would get in a living room, at dusk, with two soft table lamps. Next, we tested at 30 lux, equivalent to a 40-watt light bulb. The third and fourth tests were at 15 and 5 lux, respectively, and are very near total darkness.
We tested the Olympus Stylus 720SW on a tripod with the flash off and the white balance manually selected to the tungsten setting. The camera automatically set the ISO at 100 for the first three tests and 200 for the last and darkest test.
As seen in the images, the illumination remains fairly constant. The pictures look decent, although there is a bit of noise, which is expected. What is unexpected, however, is the color shift in the white areas. The 60 lux test shows a strongly blue-tinted white, while the 5 lux test shows an obvious red tint.
Below is a chart showing the amount of noise present at each shutter speed used in the tests. The horizontal axis shows the shutter speed in seconds; the vertical axis shows the corresponding amount of noise.
The Olympus 720SW took a 1-second exposure for the 60 lux test and produced some noise, but not as much as many other compact models. On the 30 lux test, it took 2 seconds to expose the shot and returned very similar noise results. Between these first two tests, the color error increased from 10.4 to 11.1 as the light dimmed, but the saturation remained stable. The 15 and 5 lux tests used the same 4-second exposure, but the darkest test used a higher ISO. Both dark tests garnered 93 percent saturation. Colors suffered, as the mean color error went from 12.2 at 15 lux to 13 at 5 lux. The noise on the 5 lux test was greater than that on the 15 lux test because of the higher ISO. Still, the images and general performance in low light are quite good.
Dynamic Range (4.0)
Our dynamic range test measures the ability of cameras to capture detail in bright and dark subjects simultaneously. Wide variations in brightness are a challenge to any camera, film or digital. Our standardized test involves shooting a Stouffer test target film that is lit from behind. The target shows a series of rectangles that range from perfectly clear to almost opaque. The clear rectangle appears pure white in our test shots, and the darkest rectangles end up pure black. We use Imatest software to measure how many steps of the chart show detail at two levels of quality. Our Low Quality measure steps of range with up to a full stop of noise, and High Quality measure steps with 1/10 of a stop of noise. The High Quality measure is more important. We test each camera throughout its ISO range, and most cameras do best at low ISOs.
The Olympus 720SW does not reproduce a wide dynamic range. Although its Low-Quality scores are mediocre at low ISO, and better than average at high ISO, the more important High Quality score is terrible across the ISO range.
Speed / Timing
Start Up to First Shot (7.42)
The Olympus 720SW took its sweet time starting up. It was 2.6 seconds after we first hit the power button that the 720 finally captured an image. This is a little puzzling. Many small cameras have to extend telescoping lenses or perform other mechanical operations as they start up, and those functions seem to slow down their startup. The 720 doesn't do any of those things, so we're surprised that it takes even longer to start-up than cameras that do.
Shot to Shot (9.73)
Olympus has been working on burst modes on its compact cameras, and the 720 delivers a high-speed burst that really pops along. In high, the 720SW shot 25 frames in 11.29 seconds, which translates to 2.2 frames per second. 25 frames isn't a limit to the burst -- we just stopped because we filled our media card. In regular burst mode, the 720 managed a burst of 5 frames in 3.59 seconds, for about 1.4 frames per second.
Shutter to Shot (7.98)
The 720SW imposes an inconvenient delay between the moment the shutter is pressed and the one when the picture is taken. The 720SW took 0.5 seconds to capture a shot. That's enough to be inconvenient in candid situations, and very frustrating when shooting action. 720SW users will have to learn to anticipate the action, and press the shutter a bit before the peak of action.
