The SD550 features a 3X (37-111mm in the 35mm format) f/2.8-4.9 all-glass aspherical zoom lens. This lens features Canon’s exclusive Ultra High Refractive Index Aspherical technology (UA) which produces outstanding sharpness and clarity. It allows the camera body to be even thinner and more compact than previous models with smaller zoom ratios. The UA technology produces crystal clear images at all focal lengths. When powered down, the lens is retracted inside of the body and a built in shutter closes to protect the lens.

An advanced TTL AiAF 9-point autofocus system permits the camera to automatically select the primary subject even when off-center. Focusing range is 1.6 foot (50cm) to infinity in normal mode and macro coverage is 2 to 18 inches (5-50cm) in wide angle and 12 to 18 inches (30-50cm) in telephoto. The autofocus is light-assisted and works properly even in the dark. The AF-assist illuminator also functions as the selftimer indicator.

The built in flash offers Auto, On, Off, Red-Eye Reduction and Slow-Synchro modes. Flash range is 1.6 to 16.4 ft. (50cm-5m) in wide angle, 1.6 to 9.8 ft. (50cm-3.0m) in telephoto or 1 to 1.6 ft. (30-50cm) in macro mode (with ISO set to Auto.) The focus- assist lamp also serves as the red-eye reduction lamp.

The optional HF-DC1 external flash can be used with the SD550 to double the flash range of the built-in flash. Compact and elegantly designed, the High-Power Flash HF-DC1 complements your PowerShot perfectly and requires no accessory shoe. With a strong light output (guide number 59 ft.) and wide angular field (28mm), it delivers proper illumination up to approximately 30 feet and in all zoom positions. The flash fires in synchronization with the main flash, and output is adjusted accurately and automatically.

You can frame your pictures with the color LCD or to save precious battery power you can use the optical eyelevel finder. This is a coupled viewfinder with approx. 82% coverage. It has no dioptric adjustment. Next to the finder are two LEDs that indicate the flash and focus status.

On the back is a large 2.5-inch color LCD monitor which can be used for framing, review and changing settings. Advanced features include "Quick-bright" function which switches the brightness to the highest setting by pressing the DISP button for 1 second. When shooting in dark lighting, the LCD is automatically brightened to make it easier to frame and focus on the subject.

Controls on the back: Mode Switch with positions for Play, Auto, Manual, 9 Scene modes and Movie. The Print/Share button allows you to easily print and transfer images to your computer (Windows users only). The 4-way controller lets you navigate menus and select images during playback. In record mode you press "Up" to change ISO sensitivity, press "Right" to change flash modes, press "Down" to change the drive mode and press "Left" to change the focus mode. In the center is the FUNC./SET button which gives you access to the Function menu in record mode or accepts menu options and settings. The DISP button turns the color LCD on/off and controls the amount of data displayed on it. The MENU button calls up and dismisses the menus.

Controls on the top: the Power On/Off button, the shutter release button and the zoom lens control around the shutter release. The zoom lens control also functions as the magnify and index buttons in playback mode.

The AV Out handles the monaural audio and video signal which can be connected to your TV set with the supplied cables. The high-speed USB 2.0 port for image and movie download. The USB port can also be used for direct printing to any PictBridge compatible photo printer.

The Powershot SD550 is equipped with a Secure Digital (SD) card slot and comes with a 32MB SD card. It can handle any capacity SD card up to 2GB - the spacious and speedy SanDisk Ultra II 512MB card is a good choice for this camera.

Approximate Storage Capacities

				*32MB	128MB	512MB
	Large (3072×2304 pixels)		Superfine	9	40	156
			Fine	15	64	251
			Normal	31	134	520
	Medium 1 (2592×1944 pixels)		Superfine	11	49	190
			Fine	20	87	339
			Normal	40	173	671
	Medium 2 (2048×1536 pixels)		Superfine	17	76	295
			Fine	32	136	529
			Normal	63	269	1041
	Medium 3 (1600×1200 pixels)		Superfine	28	121	471
			Fine	51	217	839
			Normal	97	411	1590
	Small (640×480 pixels)		Superfine	109	460	1777
			Fine	168	711	2747
			Normal	265	1118	4317
	Standard (640×480 pixels) (My Color (640×480 pixels))		30 fps	14 sec.	64 sec.	249 sec.
			15 fps	30 sec.	127 sec.	494 sec.
	Standard (320×240 pixels) (My Color (320×240 pixels))		30 fps	42 sec.	181 sec.	702 sec.
			15 fps	84 sec.	355 sec.	1373 sec.
	Fast Frame Rate (320×240 pixels)		60 fps	21 sec.	92 sec.	359 sec.
	Compact (160×120 pixels)		15 fps	206 sec.	869 sec.	3357 sec.

(*32MB SD card supplied with camera)

The SD550 comes with a Canon NB-3L 3.7v 790mAh lithium rechargeable battery pack. Canon claims a fully charged battery can record 160 shots with the LCD on or 550 shots with it off and a replay time of approx. 210 minutes.

The supplied 100-240V CB-2LU rapid charger plugs directly in the wall socket and charges the battery "out of the camera" which is very handy if you have a second battery (highly recommended!)  The normal charging time is 95 minutes.