Operation and controls

The S90 is one of only a few cameras to offer a high level of photographic control in a pocketable body (something it's a stretch to describe the Panasonic LX3 as), but what really makes it stand out from the crowd is the efforts Canon has put into making those controls usable in a way that doesn't get in the way of the process of actually taking pictures (something anyone who's ever had to use a menu to change an aperture or adjust AE compensation will be painfully familiar with). Offering lots of external controls, twin control dials and a decent level of customizability, the S90 gets a lot closer to the fluidity and transparency needed to really get the most from a sophisticated set of photographic functions.

Rear of camera

As with most modern compacts the rear panel is dominated by a large (3.0") LCD screen. To the right sits a tight cluster of controls including the customizable Shortcut button, the familiar FUNC/SET, DISP and MENU buttons and a freely rotating dial. Inside this dial is a four-way controller (it's not marked as such, but in menus that's what it does). This also gives direct access to AE compensation, Flash mode, Self-timer and focus mode (Auto, Macro, Manual Focus). Above the button cluster is the nearest the S90 gets to a 'grip' for your thumb to rest on.

Top of camera

It's a little fatter than your average compact, but this allows the S90's top plate to be put to use for something more than an on/off button and shutter release. Here you'll also find the main mode dial, zoom rocker, Ring Function button and over on the left, the pop-up flash.

Display and menus

The extensive menus will be instantly familiar to anyone who has previously used a Canon camera (compact or DSLR) in recent years. There are a handful of options split over two tabs, with a third tab acting as the customizable 'My Menu' page. This makes it very easy to assign your favorite menu items to the third tab, minimizing the amount of time you spend in the menu system. The user interface itself is a visual treat, with sharp, clean, sophisticated graphics and fancy playback and transition effects.

Beyond the main menu, the S90 features Canon's ubiquitous Function menu with eight icons representing major shooting settings. The functions included on the menu vary depending on which mode you're in, but tend to be fairly well chosen so that you're not inundated with options you're unlikely to change.

Pressing the display button cycles between the two screen modes and an off setting. These two settings can be customized. Here is an example of a screen with several options turned on - shooting info, grid lines and a histogram. One nice touch is that the icons briefly turn orange after you've changed any setting.
The menus allow the two display screens to be customized. The customization continues, with the ability to define the function of the shortcut button on the camera's top left corner.
Pressing the RING FUNC. button brings up this menu. The default setting (STD) is different for each mode (in P mode, for example, it controls ISO, in Tv mode the Shutter Speed etc). If you do override, the default setting jumps to the rear dial. The full auto and scene modes don't offer this option; the ring function is fixed at Step Zoom.
In all modes the functions of the rear dial and front dial are clearly indicated bottom right. A scale appears when you turn the ring. Here I'm changing ISO in P mode.
The same thing happens when you turn the rear dial (here I'm in Shutter Priority mode, with the rear dial controlling shutter speed, the front dial AE Compensation). Using the Function Ring to adjust AE compensation.
The S90 is one of the few small cameras with a genuinely usable manual exposure mode. By default the front ring and real dial control aperture and shutter speed, but if you can live with pressing the +/- button to swap functions you can have ISO on the front dial and exposure on the rear, giving remarkably fluid total control. The metering scale on the right is live (you don't need to 'half press' to activate it) and, as with AE compensation changes, the preview brightness is adjusted to give you an exposure simulation.
White balance can also be customized - in addition to the standard presets for different types of light source. Pressing the 'Disp' button while setting white balance allows fine tuning in both Blue/Amber and Magenta/Green axes.
Naturally the S90 has Canon's ubiquitous FUNC menu, though I found myself using it far less frequently thanks to the direct access afforded by all those buttons and dials. The FUNC menu provides quick access to ISO, WB, Color effect (MyColors), Flash exposure, Bracketing, Metering, Drive mode and File Size/Quality. Many of the options are fixed (greyed out) in the full auto and scene modes, and the movie mode has a slightly different set of options.
Pressing the external buttons brings up a small menu of options (this is flash mode) Focus mode.