Like its predecessors the Optio S5i is incredibly compact, and is truly pocketable. The 3x zoom lens retracts completely into the body and there is little in the way of protrusions on the body itself (aside from the small narrow grips and the single strap lug). The stylish, unfussy design, aluminum alloy construction and careful use of surface textures gives the S5i a gem-like feel that simply oozes quality; it is very well put together and offers surprisingly good handling. At around 120g fully loaded the S5i is also as featherweight as it is Lilliputian, and can easily sit in a shirt pocket or the smallest purse, making it a real 'carry anywhere' camera. As is increasingly common these days the S5i is available in a choice of colors - though in this case only three; cool silver (a bluey gunmetal grey - shown here), Indigo (bright blue) and silver. Not all colors are available in all parts of the world.
In your hand
For such a small, light camera the S5i handles surprisingly well. The milled surface used on the majority of the body makes it much less 'slippery' than shiny cameras like the Canon SD300, and it feels a lot safer for it - especially when shooting single-handed. The two tiny grips (on the front and rear of the body near the right hand edge) may look useless, but they actually work very well, and the camera feels very stable in use. The zoom and shutter controls are perfectly placed, and - unlike many ultra-compacts I've used - I didn't find myself accidentally pressing the buttons on the rear of the camera with my thumb when taking pictures.
The combined battery and SD storage compartment is found in the base of the camera on the right side under a fairly sturdy hinged cover (one of the only bits of plastic on the body). The battery held in place by a spring clip. It's also nice to see the tripod mount is near the middle of the body. The battery (which can be charged inside or outside the camera using the supplied charger 'stand') lasts for around 160 shots per charge (CIPA standard).
On the right side of the camera (from the rear) are two small ports under flexible plastic 'flaps'. The upper port is a combined mini USB and AV (audio/video) socket, the lower accepts power from the (optional) AC adaptor.
The 85,000 pixel, 1.8-inch LCD screen is fairly bright and clear (though compared to higher resolution screens it is a little 'rough'). It suffers from a slight noticeable lag and the refresh rate doesn't seem that high, but is all the same perfectly usable. It works well in all but the brightest light and is very usable in the dark too - though the image does become progressively noisier as light levels drop.
The 35-105mm equiv. lens retracts completely flush into the body and extends by around an inch when powered up. The F2.6 maximum aperture at the wide end of the zoom is very useful, but at the long end of the zoom it's F4.8, which limits its usefulness in low light situations.
The tiny optical viewfinder is clearer than many I've seen on ultra-compacts, but it's still far from ideal, and only offers around 80% coverage. As with all cameras of this type it's fine for making sure you're pointing the camera in the right direction (and for extending battery life), but for accurate framing you'll want to stick to using the LCD.
The top plate has only two buttons - the shutter release and main power (on/off) switch. Surprisingly I didn't find myself accidentally turning the S5i off every time I wanted to take a picture, given the stupid positioning of the buttons.
The small flash is powerful enough to reach around 11.5 feet at the wide end of the zoom (200 ISO). It's a little too close to the lens for our liking, meaning red-eye is a fairly common unless you use the anti-red eye setting (which uses a single pre-flash). The flash throttles down well at relatively short shooting distances, though it does tend to blow out once you get down below about 7 inches.
The S5i has a 'quick' button above the LCD screen that can be assigned to one of 11 different functions using the setup menu. The default setting is 'green mode' (auto everything point and shoot operation), but you can change this to any of the following; white balance, memory, resize, trimming, copying, format, user mode, movie mode, mode palette. You can also reassign the left/right arrow keys to one of 12 custom functions too; very useful.