Canon announced replacements to its A-series models back at CES 2011, leaving its Elph lineup untouched. That changed today, though, as Canon rolled out three new ultracompacts as well as a new compact megazoom. Oh, and Canon changed its naming system.

The PowerShot Elph 100 HS, Elph 300 HS, and Elph 500 HS all feature 12-megapixel high-sensitivity backside-illuminated CMOS sensors and a Canon Digic 4 image processor' the combination makes up Canon's HS System, hence the HS is now part of the model names. Canon did away with the "SD" and "IS" in their names as they all take SD cards now (SDHC and SDXC) and they all have optical image stabilization.

Since they all have the same processors and image sensors, the main differences are in the lenses and displays. The $299.99 500 HS has an f2-5.8 24mm-equivalent ultrawide-angle lens with a 4.4x zoom and a 3.2-inch touch-screen LCD. (It's basically a combination of the SD4000 IS and SD3500 IS.) The 300 HS will be $50 less than the 500 HS and feature an f2.7-5.9 24mm-equivalent ultrawide-angle lens with a 5x zoom and a 2.7-inch LCD in a very small body. At the bottom is the 100 HS with a 3-inch LCD and a 4x f2.8-5.9 28mm-equivalent wide-angle lens. It will sell for $199.99. All of the models can capture video in full HD.

Canon also updated the SX210 IS compact megazoom by adding the same HS System as the Elphs. The new $349.99 SX230 HS keeps its predecessor's 14x, f3.1-5.9, 28-392mm lens (35mm equivalent) and 3-inch LCD, but gets a 12-megapixel BSI CMOS sensor. It also gets a built-in GPS receiver for geotagging photos while you shoot.

Look for the Elphs and the SX230 HS to hit stores throughout March.