The basic design concept of the S100FS is still the same; it is a large SLR-style camera with a manually-operated zoom lens, a tilting monitor screen and an electronic viewfinder. Physically it is somewhat larger than the S9600, measuring 133.4 X 93.6 X 150.4mm. It's also quite a lot heavier, weighing a substantial 918g minus battery. In terms of size and weight it definitely into digital SLR territory. By comparison the Canon EOS 400D measures 126.5 x 94.2 x 65mm and weighs 510g body only. Body construction is polycarbonate plastic over a metal frame, the same as most consumer DSLRs, and build quality is very good. The extra weight and the large rubberised grip give the camera a pleasant solidity and stability, useful when shooting at lower shutter speeds. The control layout is similar to the S9600, albeit with more buttons, but it is fairly straightforward and easy to operate.
A lot of the extra weight comes from the new lens, which is significantly larger than that on the S9600, both in terms of physical size and focal length. It has a zoom range equivalent to 28 - 400mm and a maximum aperture of f/2.8 - f/5.3, specifications which compare well with super-zoom lenses available for most digital SLRs. That massive zoom range makes it a good all-rounder, covering everything from wide-angle landscapes to long telephoto.
The manual zoom action is nice and smooth, and far more pleasant to use than the powered zooms found on most other cameras, but I'm not so keen on the manual focus system. It uses an electrically-linked "fly-by-wire" system, with a focusing ring on the barrel of the lens. I found it to be unresponsive, and the viewfinder magnification which activates automatically in manual focus mode is very blocky and not sharp enough for accurate focusing.
One welcome additional feature notably absent from the S9600 is optical image stabilisation. This is pretty much an essential item on super-zoom cameras these days, and although Fujifilm was a late adopter it is now fitting IS to most of its longer lens models. The system works well, allowing sharp hand-held shots at full zoom at shutter speeds as low as 1/60th of a second, an advantage of just under 2.5 stops. This compares well with other high-end super-zoom cameras, such as the Canon S5 IS or Panasonic FZ18.
The most significant improvement is the camera's sensor. The S9600 had a 9.0-megapixel SuperCCD HR sensor of the larger 1/1.6-inch size, measuring approximately 7.7 x 5.8mm, physically larger than the sensors in most compact cameras. The S100FS goes even further, featuring an 11.1-megapixel SuperCCD HR which is even larger still. It is of the larger 2/3-inch type, measuring approximately 8.8 x 6.6mm. Physical sensor size is important, because a larger sensor means larger photocells with greater sensitivity to light, which in theory means greater colour depth and less image noise. By comparison, the sensors in most high-spec compacts measure approximately 7.2 x 5.3mm, while the APS-C sensors in most digital SLRs measure 23.7 x 15.7mm. Even the Olympus Four-Thirds sensor measures 18 x 13.5mm.