Camera comparison:  Canon S90 to Canon S100

Canon S90 on the left.  No Photoshop adjustments. 

Outdoor "landscape"  Full automatic mode. Note that the S100 (on the right) has a larger native image size.  I also think it has more accurate color.

Inside with no flash.  Full automatic mode. S90 on left. Camera iso set at 1,600.

Inside Macro mode (P setting). 

Both of the photos in this frame were taken with the S100.  The one on the right had the HDR feature activated.  Note the improved exposure of the tree and bush in the shadows on the left side. 

This photograph was taken well before sunrise (5:45 AM).  To the eye the scene was much darker than in the photo.  For example, the yellow house color looked black.  Both cameras were set at ISO=3200.

This is a magnified view of  the preceeding photo.  The S100 obviously has better low light performance.

Both of these photos were taken with the S100.  The one on the left is ISO=3200, the one on the right is ISO=6400.  (The S90 camera's maximum ISO is 3200).  I think the S100 sensor/software offers a one F-stop shutter advantage over the S90.  That is to say, the S90 at ISO 3200 looks about like the S100 at ISO 6400;