The S1 employs a high-speed and variable speed Canon Ultrasonic Motor (USM) to operate the zoom lens mechanism, a feature it shares with the new, top-of-the-line PowerShot Pro1 digital camera. The silence of the USM is particularly beneficial in movie mode to preserve and enhance the quality of the audio recording.

The S1 features a fast f/2.8-3.1 image stabilized 10x zoom lens (38-380mm equivalent in 35mm photography) that makes tack-sharp long telephoto shooting positively practical. Despite its extensive optical range, the lens is ultra-compact and retracts securely into the camera when it is powered down.

The lens is constructed with 11 elements in 9 groups including one aspherical element to reduce size and weight and ensure image sharpness, particularly at wide-angle settings. Thanks to Canon's optical Image Stabilization technology, users have the flexibility of actually shooting at shutter speeds two stops lower than would otherwise be possible.

On the side of the lens barrel you'll find the MF (manual focus) button and the IS (image stabilization) mode button.

The S1 is equipped with a single-point TTL AF system that achieves sharp focus quickly and silently. Although the AF frame is normally positioned at the center of the viewfinder, it can be moved freely to almost any section of the picture. It also features manual focus override as well as a Focus Bracketing function. Close focus is possible down to 3.9 inches at the wide-angle setting and 3.1 feet at the maximum telephoto setting, which fills the frame with subjects as small as 3 x 4 inches.

With the use of Canon's optional Conversion Lens Adapter, the PowerShot S1 IS accepts an optional Tele-Converter that increases the optical range of the lens to a maximum equivalent of 608mm and an optional Wide Converter that yields a 24.5mm equivalent at the widest zoom setting.

Our friends at Lensmate offer this machined aluminum S1 IS lens adapter that allows you to attach standard 52mm filters and lenses.

The S1 uses a high-resolution TFT color LCD with 114,000 pixels as the eyelevel finder.

The diopter is adjusted via a knob on the side. The Monitor button switches between EVF and LCD displays.

Rotate the LCD all the way forward and flip it around for framing self-portrait shots.

When the LCD is not needed it can be rotated around and positioned "face in" to protect the display from damage or greasy nose prints.

The S1 has a builtin, multi-mode E-TTL speedlight that can be set set to automatically "popup" when needed. The flash's working range (at ISO 100): 1.0 - 4.2 m (3.3 - 14 ft.) (Wide), 1.0 - 3.8 m (3.3 - 12 ft.) (Tele)

The flash has modes for normal auto, auto with red-eye reduction, forced on, forced off and slow synchro 1st curtain (leading) or 2nd curtain (trailing) timing.