Testing / Performance

Color*(7.12)*

Color performance may be the most important factor in digital camera specs. Low resolution isn't a problem for people who make small prints, and noise isn't much of an issue to users who keep the ISO setting turned low. But color matters to everyone. Bright, vivid colors are among the first things shooters get complimented on.

We use Imatest software to measure a camera's color accuracy. We photograph a GretagMacbeth color chart, which shows 24 sample colors that are both similar to real-life colors and challenging to reproduce. Imatest software analyzes the photos to show accuracy for each color, and delivers numerical results indicating the camera's overall performance.

The Olympus Evolt E-500 has color modes called Vivid, Natural, and Muted. Vivid is the default setting, indicating that Olympus knows many amateurs would rather have bright colors than accurate ones. We tested the E-500 in all three modes.

The first charts are a revised version of the GretagMacbeth chart. The large outer squares show the colors as the E-500 renders them. The inner squares show the colors as they should be rendered, and the rectangles show the ideal colors, corrected for luminance but not hue.

The second set of charts is a better indicator of the Imatest results. The background is a color space chart, and the small squares show the GretagMacbeth color plotted where they should appear on that chart. The circles show where the E-500's colors appear, and the length of the lines between the squares and the circles shows the amount of error. Colors get less saturated toward the center of the chart, and they shift hue as the position rotates. So, if the circle is farther away from the center, the camera oversaturates that color. If the circle is separated from the square either clockwise or counter-clockwise, then its hue is inaccurate.

The E-500's saturation performance is more accurate than typical cameras marketed to consumers. At the Vivid setting, it registered 103.1 percent saturation, a figure comparable to the Natural setting on many cameras. Natural is undersaturated, at 96.03 percent, and Muted is truly muted, with only 90.95 percent saturation. Color accuracy was more of a problem: Vivid mode delivered a mean color error score of 8.13. Natural was nearly the same, at 8.15, and Muted was marginally worse at 8.35. All three scores are poor. The color hue inaccuracy is most pronounced in the green and blue range, so it may not pose a big problem for users most concerned with skin tones.

Still Life Scene

Resolution*(3.53)*

Resolution is a measure of the level of detail a camera can record. It's more complicated than simply the number of pixels in the final image. We measure resolution in line widths per pixel height (lw/ph), a standard measure that allows direct comparison between all digital cameras, no matter what size their image sensors are. We photograph an industry standard resolution chart and analyze the images with Imatest software. We shoot each camera at a variety of focal lengths and apertures and report the best results we get.

The Evolt E-500 delivers 1658 lw/ph horizontally, with 12.2 percent oversharpening. Vertically, it delivered 1607 lw/ph, with 9.89 percent oversharpening. We got these results with the lens set to 33mm and f/6.3, which is toward the middle of the zoom range, and stopped down slightly from the maximum aperture. It's typical to see the best result in the middle of the range.

All cameras run an internal sharpening routine while saving images, and we report sharpening results from less than a dozen percent undersharpened to as high as 25 percent oversharpened. The E-500's 12.2 percent result bodes poorly for post-processing – users will probably run into problems in image editing if they try to sharpen E-500 images on their computers.

Noise – Auto ISO*(7.43)*

Noise is variation in color or brightness of an image, where no variation belongs. A blue sky with a grainy texture is an example of noise. We use Imatest software to measure grain, using the same images shot for our color accuracy tests. When the Evolt E-500 is set to Auto ISO, it keeps the setting down to 100 or 125, and so the camera delivers the best noise performance possible in Auto mode.

Noise – Manual ISO*(9.03)*

Low Light*(5.75)

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Speed / Timing

Start-up to First Shot (6.0)

The Olympus Evolt E-500 includes the SWF dust control system, which runs each time the camera starts up. It is meant to jar dust off the glass cover over the sensor. It takes a second or two to run, and it delays the first shot. Our best time was 3.24 seconds. That's a long time, even for compact cameras. For DSLRs, which usually take less than a second, it is very, very slow. Keep the E-500 on whenever a shot might come up.

Shot to Shot Time (6.0)

The Evolt E-500 offers a Burst mode that is capable of 2.5 frames per second (fps), in 5-frame bursts, in the top resolution. Quite a few entry-level DSLRs run between 2.5 and 3 fps. A 5-frame buffer is relatively skimpy, though. In combination, 5 frames over 1.7 seconds won't deliver a really satisfying sports action sequence, but it might help get a nice portrait of an antsy child or someone with fleeting expressions.

Shutter to Shot Time (6.0)

The great advantage of DSLRs should be the minimal delay between the instant the shutter is pressed and the instant the shot is taken. The Evolt E-500 is slow for a DSLR, with a 0.27-second delay, including focusing. A quarter-second delay makes it harder to shoot candids with the Evolt E-500.

Dynamic Range

In music, dynamic range describes the span from the loudest to the softest sounds. In photography, dynamic range is the span from brightest to darkest in a scene or photo. In both music and photography, the ability to capture a wide dynamic range is valuable, and it's not easy in either pursuit. Problems occur at either end of the range – in photography, the dark tones end up pure black and the light tones end up pure white.

We test a camera's dynamic range with a standardized procedure, using Imatest software. We photograph a calibrated test target called a Stouffer chart. The Stouffer chart is a piece of film that has a series of 40 rectangles of graduated tones. When the film is lit from behind, the darkest rectangle is 13.3 EV darker than the lightest one. This 13.3-stop range exceeds the dynamic range of every camera we have tested. Imatest software analyzes the images, counting the number of steps shown at various levels of quality. In this case, quality is measured by noise level. Low noise equals high quality, and vice-versa. The dark end of the range shows increasing noise, so the range with low noise (and therefore, high quality) is narrower than the range with more noise. Both low and high quality ranges are important. High Quality is the range that yields pleasing results for the main subject of an image, but Low Quality indicates the range that shows any detail at all –and even if the detail isn't clear, images look better with vague details in the shadows, rather than large swathes of pure black.

The Evolt E-500 scores poorly on our dynamic range test. Across the range, it records about 1/2 EV less range than Olympus's Evolt E-330, which wasn't stellar. At ISO 400, the E-500 shows only 5 EV of range at High Quality – a rating DSLRs should be able to achieve at ISO 1600, or at least 800.