Externally, the S100 looks very much like its immediate predecessors. The original S90/S95 design worked very well, and sensibly Canon hasn't done a lot to change it. The excellent multi-functional 'Lens Control Ring' that can be used to change a wide range of settings is still in place, and is accompanied by a rear control dial that no longer provides direct access to exposure compensation (as per the S95) but changes shutter speed in manual exposure mode, and exposure compensation (in concert with the dedicated exposure compensation button on the camera's rear) as well as flicking through images in review mode, menu navigation and so on.
The rear layout has been changed from the S95, most prominently to add a direct movie record button. The S95's 'Ring Func' and 'S' buttons have been consolidated to a single customizable control on the rear. The one control that no longer has direct access is the self-timer, which is now set through the 'Func' menu. The Focus and Flash modes can be set directly, and most remaining options can be accessed quickly using the 'Func' menu. This makes for a compact camera that provides at least as much external control as most entry level DSLRs. A quick switch of the top dial to the green Auto position puts the camera into fully automatic point-and-shoot mode.
The top view shows that the S100 retains the slim lines of its predecessors, and reveals the minimalist profile of the front grip. On here you'll find the On/Off button, the zoom lever surrounding the silver shutter button, and the exposure mode dial. The Ring Func button has been displaced by the GPS unit, so there's no longer any chance of turning the camera off accidentally by mistaking it for the power button.
Body Elements / What's New
The S100 gains a direct movie record button on the back of the camera underneath your thumb - however you can't control either the shutter speed or aperture in movie mode.
The 'Ring Func' button is customizable, and can take on any of the functions offered by the S90 / S95's 'S' shortcut button. We suspect many users will set it to control ISO, and leave it there.
The functions on the 4-way controller have been slightly rearranged. 'Disp' has found its way to the 'down' key, displacing the self timer into the Func menu.
The other buttons offer easy setting of macro or manual focus and flash modes, and direct access to exposure compensation no matter what the lens control ring is set to operate.
The mode dial on the top plate sees Creative Filters split out from Scene Modes, and denoted by this 'overlapping circles' icon. The S95's reduced-resolution low-light mode has disappeared.
The Movie Mode becomes slightly vestigial given the direct record button, but does offer an easy way to frame in the 16:9 aspect ratio for HD video.
The small motorized flash unit pops up out of the top plate when it's required, either automatically in the Auto and Scene modes, or manually in PASM.
The S100 sports the standard pair of connectors, USB/AV out and HDMI. The latter connection is CEC compatible, meaning you can browse through images and play back movies using your TV's remote control.
The S100 uses the NB-5L battery, shared with a number of Ixus and SX models but different from the NB-6L used by the S95. It's rated for 200 shots in CIPA standard tests.
The memory card slot is found in the same compartment, and can accept SD, SDHC and SDXC cards.
The tripod socket is positioned centrally with respect to the lens, meaning it's rather close to the battery door (which can easily be forgiven on a camera this small).
The S100's built-in GPS allows you to geo-tag all your images as you shoot, and optionally keep track of your movements by logging your location at set intervals regardless of whether you're shooting or not. Naturally it can be turned off completely if you prefer.