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Sony DSLR
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Sony DSLR-A200 Digital Camera Reviewby Steve MorgensternPublished on July 01, 2008
The A200 performed well when it comes to color accuracy, especially for a camera at such a low price. In the chart above, the original color from the Gregtag Macbeth chart is shown by the small rectangle at the right of each square patch. The color captured by the camera is shown by the large outer rectangle, while the captured color with luminance correction applied is shown by the inner square. As you can see, no glaring disparities appear anywhere in the color spectrum. An additional Imatest chart represents the reported color shift graphically:
In this chart, the recorded colors are shown by the circular markers, the ideal colors by the squares. We look for nice short lines connecting the two, indicating only a small color shift. And in the A200 chart, these lines are consistently short, with only a few noteworthy shifts in a few shades of blue. This performance stacks up nicely against other SLRs we've put through the same testing regimen, surpassing the Nikon D60 handily, and very nearly matching the results for the Nikon D300, a camera costing roughly four times as much with lens.
Sony A200 Color Scores
The A200 turned in decent results in this test, not quite on a par with the Nikon D60 and Canon XSi, but within shooting distance of these models. The maximum horizontal resolution measurement was 1803 lines, with slight undersharpening, with the lens set to a wide angle. Performance was reasonably consistent as we zoomed in, though it did fall off noticeably at the longer telephoto range. Sony A200 Resolution Scores
To test a camera's noise performance, we photograph the Gregtag Macbeth color chart at the full range of supported ISO settings, then analyze the results using Imatest software looking both for image noise at particular settings and for trends that arise as the ISO gets higher. In our manual settings test, noise levels started out at barely over half a percent and rose at a modest rate. Interestingly, the choice to turn noise reduction on has essentially no effect at all until you hit ISOs above 800, when the imaging processing software in the camera kicks in and makes a major difference.
Sony A200 Noise
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White Balance (7.87) The human mind does a great job adjusting for the different colors of light in our environment, basically filtering what the eye sees so the illumination looks white except under extreme circumstances. In fact, though, the color of light from the sun is vastly different from that cast by a household lightbulb or a fluorescent tube. A digital camera has to adjust to these differences to produce photos that look the way we remember the scenes we shoot – hence, white balance controls. We test this by using a variety of illumination sources to shoot a standard color chart and using Imatest to evaluate the results. We run two separate batteries of tests for white balance, one with the camera's automatic setting, the other using each of the system's preset values under the designated light source. In the Imatest chart below we see the same color pattern layout as the color test results above: the color the camera captured is in the outer rectangle, the color corrected for luminance is shown in the center square, and the ideal color appears in the rectangular inset to the right. Keep in mind that this chart presents exaggerated differences to make comparison easier: you wouldn't see this level of white balance shift in an actual photo you snapped. The overall white balance performance for the A200 is a decidedly mixed bag. The automatic settings had trouble with a variety of light sources, particularly shaded daylight and fluorescent illumination. Surprisingly, it handled tungsten illumination very well, which is a stumbling point for most of the cameras we test.
Preset (10.93)
Low Light (8.32) The A200 performed well in low-light environments, though two peculiarities did arise. First, we found that when shooting at 1 second under low-light conditions, the metering system produced grossly inaccurate readings (off by three or four stops), which threw off our initial results. We worked around the problem by setting the values manually, and it only occurred at that particular setting (though repeatedly), which probably indicates a software inconsistency of some kind. The second oddity: turning on noise reduction had virtually no impact on measured levels of noise. This is not a critical problem, though, since overall the A200 exhibited low-light noise levels that were perfectly acceptable across the board. For the first test we maintain a constant light sensitivity setting of 1600 ISO but vary the light level, from 60 lux (roughly what you'd find in a normal room indoors) down to 5 lux (about the light level a single candle throws off in a darkened room).
As shown above, colors didn't drift out of whack badly when shooting in low light, even down to 5 lux, and the exposures are acceptably even. The chart below indicates how noise performance varies as exposure time increases. The levels here are pretty good overall, with only modest variation from a short exposure out to 30 seconds. As for the fact that turning the noise reduction circuitry on has nearly imperceptible effects on performance, it could be worse - we've seen cameras where noise reduction produced increased noise at certain exposure settings.
When compared to other cameras we've tested, low light performance for the A200 is very competitive, with only modest differences between this camera and most of the others in the group. Again, the Canon XSi fared particularly well in our recent lab testing, and outperformed the others handily. Sony A200 Low Light
Dynamic Range (8.27)
The dynamic range of a camera indicates how well it handles the full spectrum of lighting in a single scene, from maintaining details in the shadows to holding on to tone and not blowing out in brightly lit areas. We test by shooting a backlit chart displaying patches in progressively darker shades horizontally, from pure white to solid black. These images are taken at a variety of ISO settings, analyzed using Imatest software, and the best performance detected becomes the basis for the dynamic range score. The A200 performed adequately in this test. It started out very well, in fact, at low ISO settings, but fell off more steeply than we'd like as ISO settings increased. Turning on the camera's noise reduction circuitry decreased dynamic range at high ISO settings. Also at the highest ISOs the resolution was automatically decreased, so for consistency's sake those results don't appear in our charts and graphs.
Dynamic range performance for the A200 was slightly better than the Nikon D60 or Pentax K10D. It lagged the Canon XSi by a wide margin, but the Canon proved to be an outstanding performer in this area. Sony A200 Dynamic Range
Speed/Timing – Frankly, timing tests are becoming less relevant as digital camera design and engineering improve. Where once the lag between pressing the shutter and capturing an image could drive a poor action photographer mad, for example, this gap has narrowed drastically today, even with inexpensive gear. Still, we do turn up some peculiar timing results from time to time, so we continue to test several factors here. All timing tests were conducted using a 4GB high-speed CompactFlash card, so memory bandwidth limitations should not affect performance.
Startup to First Shot (6.60)
This is one of the areas where we do still find noteworthy differences between cameras, as some models have slow system startup routines that could cause you to miss a shot. The A200 wasn't a star performer on this test, but the average startup to first shot time of 1.14 seconds is acceptable. Shot-to-Shot (2.65) Sony claims the A200 can shoot three frames per second (fps), though our tested results came up short of that mark at 2.65 fps (or looked at another way, a bit more than a third of a second between exposures). The Canon XSi, at 3.3 fps, was significantly faster, but the Nikon D60 was in the same ballpark at 2.75fps. Shutter-Shot (5.19) As mentioned earlier, shutter delay is inconsequential on most SLRs today, and the A200 is no exception. While it's nearly impossible to measure this tiny interval accurately, our testing consistently came in at less than 0.2 seconds, which earns the camera our top rating in this category. Processing (3.40) The photo you take has to go through several steps before the camera can show you what you shot on the LCD display. This test measures the elapsed time between shutter-press and image review, and the A200 was a relative slowpoke, with an average of 2.5 seconds. This compares to 1.7 seconds for the Nikon D60, though it's only slightly slower than the 2.2-second performance of the Canon XSi.
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