The camera also includes a Speed Priority Continuous Advance mode that forgoes continuous focus and exposure adjustments--they're fixed on the first shot--to boost the frame rate to 7 frames per second up from the rated 5fps. While it makes the camera sound like it outspecs the competition on a features chart, this mode has pretty limited usefulness; to stay in focus, the subject needs to either be moving in such a way that it always remains the same distance from you or always be beyond the lens' infinity focus distance, and the lighting on the subject needs to be consistent.
(You can get a complete description of the A550's features, controls and operation by downloading a PDF of the manual.)
The special speed mode doesn't seem very important, though, because the A550 does pretty well without it. It powers on and shoots in 0.4 second. To focus and shoot in good light takes about 0.3 second, and in dim light it's still a pretty zippy 0.7 second. Two sequential shots run about 0.7 second--a hair slower for raw--which rises to about 0.9 second with flash enabled. Burst shooting runs about 4.3 frames per second.
Though the A550 is the same 14.2-megapixel resolution as the cheaper A380, the A550's Exmor CMOS sensor delivers much cleaner images at all ISO sensitivities than the CCD used by its sibling. They're sharp and relatively clean, with solid exposures, at least through ISO 400. ISO 800 looks very good on my high-end, color calibrated monitor but slightly noisy on my cheapo standard-issue display. At ISO 1,600, detail starts to mush up a bit, but for the most part detailed photos can remain usable up through ISO 3,200. As is typical for its class, ISO 6,400 and higher are more emergency modes than for everyday shooting, but the A550 displays better noise suppression at these midrange ISO sensitivities than we usually see from Sony. Its ISO 6,400 shot, for example, is much cleaner than our equivalent shot with the full-frame but older A900 and A850 models. While not a complete mess, like most cameras in its class ISO 12,800 is definitely best for small sizes.
But, as we've seen repeatedly with the Sony dSLRs, the Creative Style defaults yield poor color accuracy and oversaturation, and you can't tell that's what's happening because there's no "natural" style or its equivalent. Nor does Sony tell you what the contrast, saturation, and sharpness settings are for each style; they're all listed as 0, from which you increase or decrease. With the A380, at least, the raw versions were more accurate, but the A550's raw files look as bad as the JPEGs. At first, I thought it was the Adobe Camera Raw settings, but they looked the same in Sony's mediocre Image Data Converter SR raw-processing software. Nor does that software give you a way to strip the Creative Style settings from the image. You can rectify this to a certain extent by shooting in AdobeRGB rather than sRGB, but that's not practical for many people.
Given its excellent midrange noise profile and above-average performance--two of the most important reasons to buy a dSLR--it's frustrating that the Sony Alpha DSLR-A550's awkward design and poor color rendering keep me from being able to recommend it without so many caveats.
(Shorter bars indicate better performance)
|Time to first shot||Raw shot-to-shot time||Shutter lag (dim light)||Shutter lag (typical)|
(Longer bars indicate better performance)