When it comes to picture quality, the images produced by the Canon PowerShot SX150 IS are perfectly acceptable throughout the ISO 80-1600 sensitivity range.
Predictably though, you'll get the best results by keeping under ISO 400. Pictures taken at ISO 800 exhibit noise and lack bite, and there's a distinct drop off in detail at 1600.
The Canon PowerShot SX150 IS's lens is capable of holding sharpness across the frame, though. Barrel distortion is well handled at wide-angle, and fringing is kept to a minimum. There's a subtle hint of green haloing around some high-contrast subjects, but you really have to go looking for it.
A camera with such an extensive zoom requires careful handling if you're to avoid blurred pictures. The maximum aperture of f/3.4 narrows to f/5.6 at the long end and consequently, as shutter speeds drop, the risk of camera shake increases.
Canon's integrated Image Stabiliser offers up to four stops of compensation for this – a one-stop improvement over the SX130 IS that could conceivably make the difference between a sharp shot and a soft one.
It's fairly tricky to measure the performance of the Intelligent IS system on the Canon PowerShot SX150 IS, because the camera switches between the options automatically – you can't override the selection, only switch IS on or off. However, it proved reliably effective during our tests.
Unsurprisingly, the IS isn't a complete miracle-worker at the long end of the lens as light levels drop off, and you'll still need to support the camera well.