We've referred to compact high-zoom cameras as pocket megazooms for quite some time now, but in most cases 'pocket megazooms' require the pocket in question to be fairly big. Think 'a jacket's inside pocket' rather than 'jeans front pocket'

Two of Canon's new PowerShot pocket megazooms announced today actually are jeans-front-pocket friendly -- unless you go for a skinny cut -- despite offering optical zoom ranges that compete with those of slightly bulkier rivals. The 12x-optical-zoom Canon Ixus 1100 HS (called the PowerShot Elph 510 HS in the US and other territories) has a body measuring just 21.9mm deep, while the 8x-optical-zoom Canon Ixus 230 HS (aka the PowerShot Elph 310 HS) sports a frame that's 22.1mm thick.The company also announced a third, less-pocketable megazoom today: The 12x-optical-zoom Canon PowerShot SX150 IS (which helpfully has the same name around the globe) has a beefier 45.8mm-deep body -- but unlike the two smaller pocket zooms, it offers manual exposure controls.

Canon Ixus 1100 HS: super-slim design, touchscreen, 12x zoom

Canon is billing the 12-megapixel Ixus 1100 HS as the "world’s thinnest digital camera with 12x optical zoom and a 28mm wide-angle lens." The body measures 99.0 x 58.9 x 21.9 mm. Its optically stabilized zoom lens reaches from 28mm wide-angle to 336mm telephoto in 35mm film equivalent.

The latest camera in Canon 's Ixus line, the Ixus 1100 HS offers a low-light-optimized CMOS sensor and a 3.2-inch-diagonal LCD touchscreen. Added to the touchscreen functionality of the Ixus 1000 HS from earlier this year is the ability to control the camera's shutter using the touch-to-focus controls; pressing the screen focuses on a subject, while releasing your finger from the screen fires the shutter.

The Ixus 1100 HS offers a high-speed burst mode for still images that fires off 7.8 shots per second; however, unlike previous models in the Ixis line, this camera doesn't provide a high-speed/superslow-motion video mode. In video mode, the Ixus 1100 HS shoots 1080p video at 24 frames per second, and optical zoom controls are enabled while the camera is shooting video.You won't find any manual controls for shutter and aperture, but the PowerShot Elph 510 HS looks to have the generally excellent auto exposure, scene modes, and creative filters found in recent PowerShot cameras.

New to the mix is an "Intelligent IS" stabilization system, which Canon says selects from various presets to correct camera shake more effectively in different scenarios. The system reportedly adjusts the level of shake correction automatically, depending on whether the user is snapping a wide-angle shot, a macro photo, a moving handheld shot, or a tripod-mounted shot, for example.Due in the beginning of October, the Canon Ixus 1100 HS is priced at £369 plus VAT and will be available in black, silver, or red.

Canon Ixus 230 HS: very thin design, 8x zoom and physical controls

The 12-megapixel Ixus 230 HS trades in the 1100 HS's touchscreen for physical buttons, and it has a slightly shorter zoom range (8x optical zoom, 28mm to 224mm) to go along with its smaller dimensions overall (3.77 inches wide, 2.24 inches tall, and 0.87 inches deep).

It also has a slightly faster burst-shooting mode than the Ixus 230 HS does, clocking in at 8.7 shots per second at its speediest. You handle shot composition via a 3-inch-diagonal LCD screen; the back of the camera also hosts a dedicated video-record button, a playback button, and your standard Ixus four-way directional pad/function controls. In an interesting design twist, the Auto-mode and Menu buttons reside on the side of the camera rather than the back of it. Canon moved those buttons from the back to the side in order to leave more room for the LCD screen without increasing the size of the camera or reducing the size of the display.

Like the Ixus 1100 HS, the Ixus 230 HS offers the new 'Intelligent IS' stabilization system, 1080p video recording at 24 fps with optical-zoom functionality enabled, and a low-light-optimized CMOS sensor. Slated for availability in the beginning of October at £229 inc VAT, it will be available in silver, plus some pretty horrible shades of purple, blue, green and pink.

Canon PowerShot SX150 IS: 12X Zoom, Manual Controls, and a CCD Sensor

One of these cameras is not like the others. It's the 12X-optical-zoom (28mm to 336mm) Canon PowerShot SX150 IS.

For instance, the PowerShot SX150 IS offers a 14-megapixel CCD sensor rather than the HS System's CMOS imager; most likely due to that CCD sensor, the SX150 IS lacks the fast-shooting burst mode and 1080p video capabilities of the other cameras. The PowerShot SX150 IS shoots 720p video with optical zoom enabled, and it measures a comparatively hefty 4.46 inches wide, 2.88 inches tall, and 1.8 inches deep. However, the larger PowerShot SX150 IS offers more manual maneuverability, with aperture-priority, shutter-priority, and full manual exposure controls, as well as a pop-up flash instead of the other new models' fixed, front-facing flash.

The SX150 IS also offers the Intelligent IS stabilization system found on the other cameras, and its 3-inch LCD is flanked by physical buttons and a scrollwheel to control its range of in-camera functions. Due in early September, the Canon PowerShot SX150 IS is priced at £199 inc VAT, and will be available in black or red.