With full manual exposure control and the ability to save images as raw files, the Canon PowerShot S90 may be the perfect compact camera for the demanding enthusiast photographer
It seems that contrast-detection AF has progressed about as far as it can with the technology currently available. Most high-end compact cameras now have a reasonably fast AF system, and it is often how well these systems perform in awkward lighting conditions that helps to distinguish one from another.
The S90’s AF system performs very well. In good light the AF locks onto focus quickly. When given more challenging lighting conditions, the camera has a built-in red AF focus beam that lights a scene to help it find its point of focus.
Another useful feature is Face AiAF, which detects faces and focuses on them. Once it detects a face in a scene, the AF can track it as it moves around the scene.
However, if you aren’t happy with the camera’s autofocus, or you simply wish to be creative, the PowerShot S90 can be manually focused. When in manual focus mode, the centre of the frame is magnified to aid accuracy. Manual focusing on compact cameras can often be a fiddly process, but the control ring of the S90 makes it simple and it goes some way to replicating the feeling of manually focusing an SLR lens.