Olympus 720 SW Exposure

Saturation & Hue Accuracy
Oversaturated reds and magentas, undersaturated yellows, yellow-greens, and purples. Fairly accurate hue, though magenta is shifted toward red.

Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life. The Olympus Stylus 720 SW did oversaturate the strong reds, but undersaturated other colors, including yellows, yellow-greens, and purples. The undersaturation in yellow-green colors translates into somewhat lifeless-looking foliage colors. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc. The Stylus 720 SW actually rendered skin tones a little on the pale side, without any strong pink or warm casts.

The other important part of color rendition is hue accuracy. Hue is "what color" the color is. Here, the Stylus 720 SW performed pretty well, but did shift some purples toward magenta, and magentas toward red somewhat.

Exposure and White Balance

Indoors, incandescent lighting
Good color with the Incandescent white balance setting, about average exposure compensation required.

The Stylus 720 SW's Auto white balance mode produced very warm results (almost a sepia tone), but the Incandescent setting actually produced very nice color overall. Exposure accuracy was about average, with the camera requiring a +1.0 EV exposure compensation boost to get bright results. (About what most cameras we test need on this shot.) Colors are a little dark, resulting in a dark, purplish tint on the otherwise bright blue flowers. (A very common outcome for this shot.) Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulb, a pretty yellow light source, but a very common one in typical home settings here in the US.

Outdoors, daylight
Slightly warm color balance, and slightly dark colors outdoors, but a bit better than average exposure accuracy.

Outdoor shots generally showed accurate exposure, but with hot highlights and high contrast. Shadow detail was limited, with visible noise, but not beyond our expectation for such high contrast exposures. The camera typically required less exposure compensation than average among consumer digital cameras.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
High resolution, 1,400 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,400 lines per picture height, though one could argue for closer to 1,500 lines. Extinction didn't occur until past 2,000. (The camera produced a few slight color artifacts at lower line frequencies though, visible in the full-sized res target shots.) Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail. Beware that while you might be able to make out what looks like distinct lines at numbers higher than those we've mentioned here, the camera is just doing its best to continue interpreting the lines. If you zoom in and follow them from the wider portions, you'll see the lines converge and reappear several times, so the lines you see at 1,800 and higher are really only artifacts generated by the camera's imaging system.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Fairly sharp images overall, though a moderate amount of edge-enhancement in high contrast shots and some noise suppression in the shadows.

The Stylus 720 SW's images are fairly sharp overall, with edge-enhancemment artifacts only visible in areas of particularly strong contrast: Notice the slightly lighter "halo" in the sky where it meets the dark line at the edge of the roof in the crop above. (Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.)

Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears. The crop above right shows this fairly clearly in areas where the contrast between adjacent strands of hair is relatively low. Still, some individual strands are visible, and the effect isn't too noticeable on even moderate-size prints (8x10 inches or smaller).

ISO & Noise Performance
Moderate noise at the normal sensitivity settings, very high noise that blurs detail at the higher settings.

The Stylus 720 SW's lower ISO settings produced moderate noise, though with moderate blurring in the dark areas. As the ISO setting increases, so does the noise level and the amount of blurring that results. Images at ISO 400 are soft but perhaps usable for wall display at 8x10 inches. At ISOs 800 and 1,600, the images are very blurry, with stronger and brighter noise artifacts. ISO 800 and higher shots are only usable for 4x6 inch snapshot prints, and even there the softness and noise are still somewhat apparent.

Extremes: Sunlit and low light tests
High resolution with good overall detail, but somewhat high contrast as well. Pretty good low-light performance, capable of capturing bright images under average city street lighting and slightly darker conditions.

Sunlight:
Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

The Stylus 720 SW did produce rather high contrast images under the harsh lighting above, though it also held onto a fair amount of highlight and shadow detail. Some noise suppression is visible in both shadows and highlights, which aids the loss of detail in these areas. Overall exposure was pretty good at +0.7 EV, slightly less than the average amount of exposure compensation required on this shot. (In "real life" though, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.)

Low light:
The Stylus 720 SW performed fairly well in low light, capturing bright images down to about 1/4 foot-candle (about 1/4 as bright as average city street lighting at night). Color was somewhat warm with the Auto white balance setting, however. The image at 1/4 foot-candle was also a bit noisy, because the camera automatically increased its light sensitivity to ISO 200 for that shot. The camera's autofocus system worked well, able to focus on the subject down to the 1/8 foot-candle light level without assistance (about 1/8 as bright as average city street lighting at night). Do keep in mind though, that the longer shutter times associated with Night Landscape mode absolutely demand the use of a tripod or other camera support to get sharp photos. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

Coverage and Range
A fairly weak flash with a limited range. The camera underexposed our standard shots slightly, and exposure compensation had no effect on flash exposure.

Flash coverage was somewhat uneven at wide angle, and dim though more uniform at telephoto. In the Indoor test, the flash on the Stylus 720 SW underexposed our subject at its default setting slightly, and the exposure compensation adjustment turned out to have no effect on flash exposure. (The shot above at +1.7EV is essentially identical to the shot taken at the default setting.) The camera's Night Portrait mode produced slightly brighter and more even results, though with a much stronger orange cast from the room lighting. The best results here were achieved with a +1.3 EV exposure boost.

Even at eight feet, our closest test range, flash power was a bit weak. Flash intensity only decreased from there, resulting in a very dim exposure at 14 feet.

Print Quality
Good print quality, slightly muted color, usable 11x14 inch prints. Very high ISO settings work OK for 4x6 prints, ISO 400 shots are soft but usable as large as 8x10 inches.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon i9900 studio printer, and on the Canon iP5200 here in the office. (See the Canon i9900 review for details on that model.)

The Olympus Stylus 720 SW delivered enough resolution to make decent-looking prints as large as 11x14 inches. It's unusual in that it sports high-sensitivity modes with ISO ratings as high as 1600. As you'd expect though, images shot at these very high-ISO settings are very soft with lots of image noise visible in them. That said though, we were surprised to find that the ISO 1600 setting produced acceptable snapshot-quality 4x6 inch prints. (They wouldn't win any image-quality prizes, but they'd certainly do for recording memories. - And even limited to 4x6 printout, ISO 1600 shots from a pocket-sized digicam are pretty unusual.) At slightly lower ISO settings, we felt that most users would be happy with 8x10 inch prints from images shot at ISO 400 with the 720SW.

Color-wise, we found the Stylus 720's photos definitely have more understated color than most consumer cameras on the market. In isolation, they really don't look bad at all, but when you hold them next to prints from some competing models, they can look a little dull. (Of course, this may not be a bad thing, if you're someone who's tired of the over-bright color of most consumer cameras these days. In many cases, the understated rendering of the 720SW is actually closer to reality than the over-hyped color most consumers prefer.)