Digital Cameras
Canon PowerShot A200
Test Images
(Original test posting: 07/16/02)
| I've begun including links in our reviews to a Thumber-generated index page for our test shots. The Thumber data includes a host of information on the images, including shutter speed, ISO setting, compression setting, etc. Rather than clutter the page below with *all* that detail, I'm posting the Thumber index so only those interested in the information need wade through it! |
Outdoor
Portrait:
Sharp details and very good color, but slightly dark midtones. The extreme tonal range of this image makes it a tough shot for many digicams, which is precisely why I set it up this way. The object is to hold highlight and shadow detail without producing a "flat" picture with muddy colors, and the A200 did a good job. The shot at right was taken with a +0.7 EV exposure compensation adjustment, which preserved highlight details while brightening the midtones slightly. Midtones are still a little dark, but increasing the exposure compensation to +1.0 EV lost too much highlight detail. I chose the Daylight white balance setting as the most accurate, though the Auto setting also produced good results (just slightly cool). Skin tones look pretty much dead on, and the blue flowers are pretty accurate as well. (This is a difficult blue for many digicams to interpret, and the A200 does give it some odd tints in the shadows, but overall it's a very good job.) Resolution is moderately high, and details are sharp. The shadow areas show strong detail as well, with low noise. To view the entire exposure series from +0.3 to +1.0 EV, see files A20OUTDP1.HTM
through A20OUTDP3.HTM on the thumbnail index page. |
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Severe distortion from the fixed focal length lens, but great detail
and resolution. Results are similar to the wider shot above, but the A200's fixed focal length lens distorts Marti's features in this closeup shot. The level of fine detail in the model's face and hair is excellent, with sharp definition. Detail remains strong in the shadow areas, with low noise. The main shot was taken without an exposure compensation adjustment, which produces slightly dark midtones, but holds onto highlight detail. |
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Requires an exposure adjustment for good illumination. The A200's flash was slightly dim at the camera's default exposure setting. An orange cast from the household incandescent lighting affects the color balance of the entire image (a common occurrence with this shot). Boosting the exposure compensation to +0.7 EV brightened the exposure and decreased the orange cast slightly, producing more accurate color on both Marti and the flowers. (Adjusting the exposure to +1.0 EV overexposed somewhat.) I also shot with the camera's Slow Sync flash mode, which allowed more ambient light into the image with a slightly longer exposure time. While the extra light brightens the image, the orange cast is much stronger. (Since the camera has set its white balance for the flash, rather than the room lighting.) Additionally, the longer exposure time results in a slightly blurred image, from Marti's movement. (At 1/13 of a second, this is a pretty long exposure, even with the camera mounted on a tripod.) The best results were again achieved with a +0.7 EV exposure compensation adjustment. (Click here for sample images at zero and +1.0 EV.) |
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This shot is always a very tough test of a camera's white balance capability, given the strong, yellowish color cast of the household incandescent bulbs used for the lighting. The A200's Auto white balance option had a hard time with this lighting, producing a warm color cast with a sepia tint. The Incandescent setting produced much more accurate results, though still with a very slight warm cast. (I actually prefer a slight warm cast in this shot, to represent the warmth of the incandescent lighting. I'd call the A200's handling of this nearly perfect.) Overall color looks good, and skin tones are nearly accurate. The blue flowers are dark, but the rest of the flower bouquet is about right. The main shot has a +1.0 EV exposure compensation adjustment. (Click here for a sample image at zero exposure compensation.) Really a surprisingly good job for an entry-level camera, on a very difficult subject. ISO Series:
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High resolution with good detail, and accurate color. The A200's Auto white balance setting produced the best color here, though the Daylight setting also produced good results (with just a slight yellow cast). Resolution is moderately high, with a lot of fine detail in the tree limbs above the roof and in the shrubbery in front of the house. Details are just a hint soft throughout the frame, with increased softness in the corners. Contrast is a little high, which helps define some of the softer details in the fine foliage in front of the house. A little soft, but all in all, another very nice job. |
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This image is shot at infinity to test far-field lens performance. NOTE that this image cannot be directly compared to the other "house" shot, which is a poster, shot in the studio. The rendering of detail in the poster will be very different than in this shot, and color values (and even the presence or absence of leaves on the trees!) will vary in this subject as the seasons progress. In general though, you can evaluate detail in the bricks, shingles and window detail, and in the tree branches against the sky. Compression artifacts are most likely to show in the trim along the edge of the roof, in the bricks, or in the relatively "flat" areas in the windows. This is my ultimate "resolution shot," given the infinite range of detail in a natural scene like this, and the A200's fixed focal length lens limits its capabilities here. Resolution is reasonably good, as the tree limbs above the roof and the shrubbery in front of the house show a lot of fine detail. Details are a little soft, however. The A200 picks up the stronger details in the white trim around the bay window, though the more subtle ones are lost due to the harsh sunlight. There's also a fair amount of detail in the brick pattern of the shadow area above the front porch, meaning the A200 likely has a good dynamic range. (It's hard to determine how much detail is there, given the fixed focal length lens and shooting distance.) Color looks about right, though the greens look a bit oversaturated, and the red values a little undersaturated. The table below shows our standard resolution and quality series, followed by an ISO series. Resolution Series:
ISO Series:
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Lens Zoom Range Typical fixed focal length performance. I routinely shoot this series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (none, in this case), and at full telephoto with the digital zoom enabled. The A200's lens is equivalent to a 39mm lens on a 35mm camera, which equates to a slight wide angle. Following are the results at the normal setting (wide angle), as well as at 2x and 4x digital telephoto settings. As you'd expect, the digital zoom shots trade off a lot of detail for the magnification.
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Very good color with Auto white balance, with moderately high resolution. This shot is often a tough test for digicams, as the abundance of blue in the composition often tricks white balance systems into producing a warm color balance. The A200's Auto white balance performed well here, though the Daylight setting produced a slightly warm tone. Skin tones look good with the Auto white balance, and the blue robe is about right as well (though with some faint purple tints in the deep shadow areas, a common problem among digicams with this shot). Resolution is fairly high, with good detail in the embroidery of the blue robe, flower garland, and beaded necklaces. |
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The A200 performed very well in the macro category, capturing a minimum area of just 2.2 x 1.65 inches (56 x 42 millimeters). Detail is strong on the coins, dollar bill, and brooch, with high resolution. Details are slightly soft, but still well defined. Some corner softness is present in all four corners, but the effect is slight. Color looks about right with the Auto white balance, and exposure is good. The A200's flash had trouble throttling down for the macro area, creating a hot spot in the top left corner and dark shadows in the bottom of the frame. |
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Accurate color, though slightly overexposed. The Auto white balance setting produced pretty accurate color here, while the Daylight setting resulted in a slight warm cast. The large color blocks are about right, though saturation is just a little weak. Exposure is a bit bright, but the A200 still captures the subtle tonal variations of the Q60 target well. The shadow area of the charcoal briquettes shows moderate detail, with low noise. Overall, a good job. |
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Low-Light Tests Sensitive enough for average city night shots, and slightly darker situations. The A200 features automatic exposure control, but a range of ISO settings enhance its low-light shooting abilities. With the camera's sensitivity set to ISO 400, the A200 captured usable images at light levels as low as 1/4 foot-candle (2.7 lux), though image noise was high. At ISO 200, images were usable as low as 1/2 foot-candle (5.5 lux), with moderate noise. Set to ISO 100, the A200 captured usable images only as low as one foot-candle (11 lux), equivalent to typical city street lighting at night. Finally, at ISO 50, the A200 captured usable images only as low as two foot-candles (22 lux). Noise was minimal at the 50 and 100 ISO settings. Color was nearly accurate, though cool, in most shots. The table below shows the best exposure we were able to obtain for each of a range of illumination levels, at each ISO setting. Images in this table (like all of our sample photos) are untouched, exactly as they came from the camera.
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Flash Range Test Slightly low intensity, falls after 9 feet, but reasonably bright at 14 feet. The A200's flash was brightest at eight feet from the test target, and decreased slightly in brightness from nine feet on out to 14 feet. The flash was still somewhat effective at 14 feet, but the decreased brightness resulted in a warm cast. I'd call the flash range at about 8-9 feet. Below is our flash range series, with distances from eight to 14 feet from the target.
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ISO-12233 (WG-18) Resolution Test
The A200 performed about average for its two-megapixel class on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 400 lines per picture height vertically and around 600 lines horizontally. I found "strong detail" out to 750-800 lines. "Extinction" of the target patterns occurred at about 1,000 lines. Optical distortion on the A200 is moderate, as I measured a 0.63 percent barrel distortion. This is higher than average for fixed focal length lenses, which as a class generally show lower distortion than zoom lenses at the same focal lengths. Chromatic aberration is practically nonexistent, showing barely one pixel of light coloration on either side of the target lines. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) The strongest optical distortion was some corner softness, most visible in the House and Macro shots. Resolution Series, Wide Angle
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Viewfinder Accuracy/Flash Uniformity A nearly accurate optical viewfinder and LCD monitor. The A200's optical viewfinder is a little tight, and its view seems to be shifted upward pretty radically (meaning that the final frame is shifted downward). The shift is so severe though that I wonder if I had the camera set up properly. - I'll repeat this test though, to make sure I didn't have the camera misaligned when I shot it. The LCD monitor proved to be very accurate, as I measured about 99 percent frame accuracy. Given that I generally prefer LCD monitors to be as close to 100 percent accuracy as possible, the A200 does an excellent job here. Flash distribution is slightly uneven, with a little falloff in the corners and at the edges of the frame, but it's not too bad.
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