Compared to the Canon PowerShot G3

The PowerShot G3 is a fairly obvious choice for comparison, it is a camera which is generally accepted as the best four megapixel. It also shares its sensor and image processing algorithms with the S400. Normally we would use aperture priority to get optimum sharpness from the lens, however as the S400 doesn't have an aperture priority mode both images were taken in the standard 'Manual record' or Program AE modes.

Studio scene comparison

• Canon PowerShot S400: Manual record mode, ISO 50, Default Parameters,
  Manual preset white balance
   
• Canon PowerShot G3: Program AE exposure mode, ISO 50, Default Parameters,
  Manual preset white balance

Canon PowerShot S400	Canon PowerShot G3
ISO 50, 1/8 sec, F3.5	ISO 50, 1/20 sec, F2.2
1,536 KB JPEG	1,618 KB JPEG

Considering that both cameras used their maximum aperture at the selected focal length the results are very good. The PowerShot G3 has slightly better resolution, has a sharper lens and a little more 'punch' to its images. That said the S400 really isn't far behind, indeed in the majority of well lit outdoor 'point and shoot' type images I'm sure it would be difficult to distinguish the S400 image from one taken by the G3.