優點:
Excellent resolution, best of the ultra-compact four megapixel class
Good metering, good tonal balance which maintains shadow detail
Good natural light white balance, strong and balanced colors
Four megapixels, three times zoom in the same size case as the S230 (3 mp, 2x zoom)
Control over cameras internal processing algorithms (saturation, tone, sharpness)
Low noise at ISO 50, not as clean at ISO 100, more sensitive than rated value
Excellent build quality, new body material is stylish, protective and scratch free
Easy to understand controls, good layout (although I wasn't a fan of the small mode dial)
Good shot-to-shot times, fast startup times thanks to the quick extending lens system
Bright, detailed LCD monitor with anti-reflective coating
Long shutter feature for exposures of up to 15 seconds
Long movie clip mode with fast CF cards (up to 3 minutes including audio)
Optional histogram in record review and play mode
Very fast 10x image magnification in play mode
Voice annotation ('Sound Memo') feature
Orientation sensor, although JPEG's are only tagged not rotated
Good battery life, better than PowerShot S330 with same battery
缺點:
Annoyingly small and stiff mode dial
Noise at ISO 100 worse than the competition (Although the S400's indicated ISO 100 is equivalent to many other digital camera's ISO 200)
Lens can be soft at maximum aperture, especially in corners
AF assist lamp didn't produce significantly better results in our test
Average macro performance (distortion because optimum is at wide angle)
Slight chromatic aberrations at or around maximum aperture
Moderately underexposed flash shots
Jagged diagonals visible on resolution chart, although not yet seen in 'every day' shots
Very few manual controls for the money