Canon PowerShot S90 review
The last few S-series models have adhered to a similar design, however the S90 strays from the herd somewhat. Gone is the sliding lens cover, replaced by a more simple streamlined design similar to Sigma's DP range, with a reassuring build quality.
The ring around the lens, which on other compacts is sometimes used for mounting conversion lenses, may be rotated to adjust a number of functions, including the zoom, focus, sensitivity and white balance. Although quite simple in concept, this is perhaps one of the most ingenious uses of space on any recent compact.
The button for switching between the S90's different customisations, however, is placed where we'd logically expect to find the power button. Granted, the power button is right next to it, but it's much smaller and, considering the frequency with which it is used, it isn't entirely comfortable to reach with your shooting hand. It's also a little annoying that the mode dial is both small and a little stiff, and the raised area behind it on the back allows for little purchase with the thumb when used.
Should you wish, you can assign a custom function to the ‘S' button for quick access, while rotating the menu pad during shooting allows you to adjust a particular setting such as exposure compensation or shutter speed in fine increments. Although I found this way of working effortless, I also found that the dial's looseness meant that I would often unwittingly adjust this - shifting the exposure up or down by a 1/3EV stop or so, for example - only noticing after I had taken a few images.