Olympus Stylus 830

Color (6.36)
Have you ever known somebody who owned a camera that always seemed to make people look unattractive in photos? This was likely due to poor color accuracy, which can make skin tones very pale, or extra red. Poor color accuracy affects all other aspects of photos as well, such as sky blues, foliage greens, or sunset colors. We test camera color accuracy by photographing an industry standard GretagMacbeth ColorChecker test chart, and comparing the colors the camera reproduces with the known colors of the test chart. The ColorChecker contains 24 tiles of color from all around the color spectrum.

The image below represents the Olympus Stylus 830’s color accuracy. The outer squares show the colors the Stylus 830 reproduces, the inner squares show the ideal colors of the ColorChecker corrected for luminance, and the small inner rectangles show the ColorChecker colors at a perfectly even exposure. This test is conducted in bright, even studio lights, with the camera set to Tungsten white balance (there is no manual white balance option), resulting in the most accurate colors possible for the camera.
 

Comparing the outer squares with the inner squares, you can see that not all of the color tiles blend together. Greens and yellows are especially undersaturated. This information is shown more quantitatively in the graph below. The known colors of the ColorChecker are shown as squares on the color spectrum, while the corresponding colors the Stylus 830 reproduces are represented by circles. The length of the lines connecting the circles and squares indicate the amount of color error.

The graph confirms that several of the yellows and greens are drastically shifted. The blues are shifted too. This amount color error is unacceptable. It will have a visible effect on blue skies and green foliage, making them look unnatural and dulled. Tiles 1 and 2 (which represent skin tones) are significantly shifted towards red, bringing out the red in people’s faces, which is generally not an attractive effect. The combination of erroneous colors results in a poor color score for the Stylus 830.

Still Life Sequences
Click to view the high-resolution image


Resolution (7.54)
To test resolution, we photograph an industry standard resolution test chart at varied focal lengths and exposure settings. We run the photos through Imatest, which measures resolution in terms of line widths per picture height (lw/ph), which refer to the number of equally spaced, alternating black and white lines that can fit across the image frame before become blurred.

Click on the chart above to view the full resolution image

The 8-megapixel Stylus 830 performed best at ISO 64, f/4.2, and a focal length of 12mm. The camera resolved 1810 lw/ph horizontally with 4.1 percent oversharpening, and 1614 lw/ph vertically with 3.4 percent undersharpening. These are impressive numbers, yet despite the small amount of sharpening applied the images still contain some white "ghosting" lines along edges of high contrast. Also, the photos are quite blurry along the bottom of the frame, showing that the camera can’t maintain sharpness across an entire photo. Overall, the Stylus 830 scores well in resolution, but its important to remember edges of photos may be blurry. This is especially important if you plan to make large prints, or crop and enlarge.

Noise – Manual ISO (4.75)
Noise refers to the ugly grainy or splotchy pattern that shows up in digital photos, especially at high ISO speeds. High noise levels can obscure details in photos. We test noise levels by photographing our test chart under bright even studio lights, at every ISO speed a camera offers. We analyze the photos with Imatest, which measures noise levels in terms of the percentage of image detail it drowns out.

The Stylus 830 keeps noise levels very low from ISO 64 to 200, but has increased noise at higher ISO speeds. Images taken at high ISO settings show evidence of some noise smoothing, which lowers noise levels but destroys image detail and affects sharpness. Despite this, it’s not as much noise smoothing as some competing cameras. The Stylus 830’s noise is composed almost entirely of broad splotches of color, especially blue. This noise is quite ugly, but not as distracting as some other cameras.

Noise – Auto ISO (2.03)
We also photograph the same brightly lit chart with the camera set to Auto ISO. In our studio lights, the Stylus 830 chose ISO 200, yielding a moderate amount of noise. This camera can be trusted to keep noise levels relatively low when set to Auto ISO.

White Balance (5.57)
A camera's color accuracy relies heavily upon white balance accuracy. All kinds of light sources have different color casts to them, from outdoor sunlight to indoor fluorescents. We test white balance accuracy by photographing the ColorChecker test chart under four different types of light: flash, fluorescent, outdoor shade, and tungsten. We test the auto setting as well as the appropriate presets found in the White Balance menu.

Auto (3.80)
Set to auto white balance, the Stylus 830 is inaccurate under flash, fluorescent, and tungsten lights, but mediocre under outdoor shade. This camera does not white balance well, which results in ugly color casts. The images below show the color casts.

Auto WB - Flash Illumination

Auto WB - Fluorescent Illumination

Auto WB - Shade Ilumination

Auto WB - Tungsten Illumination

Preset (7.34)
Using the presets, the Stylus 830 fares a little better. Under tungsten light, white balance accuracy is still poor, but under white fluorescent light (set to Fluorescent "3") and outdoor shade (set to Cloudy) it is quite accurate. The lesson here is to use the Stylus 830’s white balance presets. They perform much better than the auto white balance setting.

Fluorescent - Fluorescent Illumination

Shade - Shade Illumination

Tungsten - Tungsten Illumination

Low Light (5.43)
We saw how the Stylus 830 performs under bright studio lights; now let’s see how color accuracy and noise levels fare when the lights are dimmed. We test low light performance by photographing the ColorChecker chart at light levels of 60, 30, 15, and 5 lux. 60 lux is about as bright as a room lit softly by two table lamps, 30 lux corresponds to a room lit solely by a 40 watt bulb, 15 lux is as bright as a room lit by a television screen, and 5 lux is quite dark and tests the limits of a camera’s sensor. All shots are taken at ISO 400.

Low Light Tests
60 Lux	30 Lux
15 Lux	5 Lux

The Stylus 830 cannot properly expose at 5 lux, showing its limits in low light. Color accuracy is very good in low light, surprisingly better than its accuracy in bright light. Noise levels are quite high, though, and show that you should keep the ISO speed as low as you can.

We also test low light performance for long exposures at ISO 400, but the Stylus 830 can only slow its shutter to 0.5 seconds at this ISO speed (it can go only as long as 4 seconds in Night Scene mode). This is not a good camera to use for long exposure experimentation. Overall, the Stylus 830 scores worse than average for low light due to its 5 lux limit, high noise levels, and limited long exposure ability.

Dynamic Range (6.44)
Dynamic range is an important factor in image quality that describes how well a camera can discern detail in high contrast scenes. This is especially important for wedding photos (white dress and black tux) and outdoor landscapes or portraits in bright sunlight (bright highlights and dark shadows). Cameras with poor dynamic range will blow out highlights and leave shadows completely black, while cameras with good dynamic range will show detail in both. We test dynamic range by photographing a backlit Stouffer test chart at all ISO speeds. The Stouffer chart is made of a row of gray rectangles ranging from brightest white to darkest black. The more rectangles the camera can distinguish, the better its dynamic range.

The Stylus 830 has very good dynamic range from ISO 64 to 200, but its performance falters at higher ISO speeds. Dynamic range is closely associated with noise levels, which obscure image detail, especially in dark areas of a photo. Overall, the Stylus 830 has impressive dynamic range, and scores well compared to other cameras we have tested this year.

Speed/Timing – All speed tests are conducted using an Olympus 256MB xD-Picture Card, with the camera set to SHQ, unless otherwise noted.

Startup to First Shot (8.4)
The Stylus 830 turns on and fires its first shot in 1.6 seconds, which is quite speedy. This is great for those moments when you need to capture something unexpected.

Shot-to-Shot (9.1)
In its normal Burst mode, the Stylus 830 takes 3 shots, each 0.9 seconds apart. This isn't very quick; there are other point-and-shoots on the market that shoot 2 frames per second (fps) for longer durations. The Stylus 830 also has a HI Burst mode, which takes shots every 0.2 seconds for 25 shots. However, HI mode is only available at a reduced image resolution. 

Shutter-to-Shot (9.0)
The camera has no measurable lag when the shutter is held halfway down and prefocused, but a lag of 0.4 seconds when not prefocused.

Processing (5.2)
It takes 2.4 seconds to fully process one 3.2 MB SHQ shot taken at ISO 100.

Video Performance (3.70)
Bright Light – 3000 lux
We test video quality by capturing footage of our color charts, lit to 3000 lux. Under these bright tungsten lights, the Stylus 830 suffers from extreme color error when set to auto white balance. Luckily, white balance can be adjusted in Movie mode. Noise levels are very low at 3000 lux.

Low Light – 30 lux
With the lights dimmed, the Stylus 830 has better color accuracy, though it is still poor. Noise levels, however, stay quite low in low light despite the difficulty the camera has exposing.

Resolution
We also record footage of the resolution chart lit to 1700 lux. In Movie mode, the camera resolves 175 lw/ph horizontally with 11.7 percent undersharpening, and 409 lw/ph vertically with 0.4 percent oversharpening. These are very low numbers, even for video, and you can see the poor resolution in the crops below.

Outdoor Motion
We took the Stylus 830 out of the lab to record footage on the street to see how it handles motion of moving cars and pedestrians. The 830’s video shows many of the video quality problems we see in digital camera video these days: streaky highlights, flashing exposure, stuttery motion, soft focus, and dull colors. The bright side is that the camera exposes quite accurately. Yet these issues, coupled with the fact that the Stylus 830 can only take videos as long as 10 seconds at full resolution, means that you should look elsewhere for a camera to shoot videos.