from DP review
http://www.dpreview.com/reviews/canon-powershot-d20
Conclusion and samples
http://www.dpreview.com/reviews/canon-powershot-d20/5
Canon PowerShot D20
This is the first in a series of short underwater/rugged camera reviews on DPReview. We're testing the cameras concurrently, and once all six cameras have been reviewed, we'll publish a roundup of the class, comparing them directly.
While other camera manufacturers have been making rugged cameras for many years, Canon didn't enter the market until early 2009 (preferring to create optional waterproof housings for many of its 'regular' compacts instead). Canon's first truly waterproof digital compact camera, the PowerShot D10, had a rather unique (and chunky) design, but its solid performance photo quality earned it a 'Highly Recommended' badge in our 2009 Waterproof group test.
Three years later, the PowerShot D20 emerged, whose colorful, curvy but less bulbous design appears to have been be inspired by tropical fish. The D20 offers a host of improvements over its predecessor, that include the use of a CMOS sensor (which Canon touts as 'high sensitivity'), plus a 5X zoom lens (versus 3X), larger/sharper LCD, built-in GPS, and 1080p video recording. While the D20 can be submerged as deep as its predecessor underwater (10 meters), it's slightly more shock resistant and able to take a slightly higher drop than before (1.5 versus 1.2 meters).
Specification Highlights
12.1 effective megapixel BSI-CMOS sensor
F3.9-F4.8, 28-140mm lens (5X)
Optical image stabilization with 'Intelligent IS' feature
3.0 inch LCD with 461,000 dot resolution
Built-in GPS with logging function
Waterproof to 10m, shockproof from 1.5m, freezeproof to -10C
1080/24p movie mode
While the D20 has the same number of pixels as its predecessor - that's 12.1 million - its use of backside illumination technology promises better low light picture quality. That said, the D20's lens is on the slow side, with a maximum aperture range of F3.9-F4.8. This compares especially badly next to competitors like the Pentax WG-3 and Olympus Tough TG-2 (at least at wide-angle) - so the sensor has its work cut out for it.