Performance is mixed with the SD990 IS, but respectable overall and generally better than its predecessor. From off to first shot takes nearly 2 seconds, which isn't great and slower than before. At between 0.5 and 0.6 second under most conditions, shutter lag is pretty good, and its typical shot-to-shot time is on par with the category at 1.9 seconds. Turn on the flash though and you'll be waiting 3.6 seconds between photos. Continuous shooting averaged a decent 1.3 frames per second.
Photo quality is consistent with other Canon SD-series cameras: excellent. Colors are accurate and well saturated, and exposures tend to be accurate, even in some tough situations. Canon does an excellent job of keeping ISO noise under control through ISO 200. At ISO 400, noise becomes noticeable on monitors, but shouldn't cause problems with prints and doesn't cause any noticeable loss of shadow or fine detail. At ISO 800, noise becomes much more noticeable and some, though not all, shadow detail is lost while most fine detail remains. You should still be able to get decent prints, especially at smaller sizes. At ISO 1,600, noise becomes very heavy and most shadow and fine detail is lost. My problem is that, again, the SD880 IS produces equally excellent photos with its 12-megapixel resolution. The 15-megapixel doesn't seem to be offering up any added value. Also, the lens exhibits noticeable barrel distortion on the left side.
In the end, there's nothing seriously wrong with the SD990 IS, particularly if you're buying it for the photo quality and its compact design. On the other hand, most, if not all, the Digital Elphs offer similar quality. The Quick Shot mode turned out to be more useful than I initially thought; you just have to be aware that the viewfinder isn't giving you nearly 100 percent of the picture. And unless you really want the limited manual options and a viewfinder, the SD880 IS is a better option.
(Shorter bars indicate better performance)
|Time to first shot||Typical shot-to-shot time (flash)||Typical shot-to-shot time||Shutter lag (dim)||Shutter lag (typical)|
(Longer bars indicate better performance)