Below are sample crops from an indoor photograph of a book-cover at each of the Fuji Finepix s100's ISO settings. A crop from the Fuji Finepix F100fd at the closest ISO setting is shown next to each Fuji S100FS's crop. Images below are all unmodified 100% crops from their respective cameras taken at the highest quality setting. ISO and white-balance were set on camera, everything else was left on automatic.
These crops help determine which ISO settings can be acceptably used on these cameras. As noise increases, most cameras compensate with noise reduction which introduces softness. The result is that, while you can partly reduce noise at the expense of details, the maximum acceptable print size gets smaller as ISO is increased. The point at which a print become unacceptably noisy is a matter of personal taste. That being said, both these Fuji digital camera deliver outstanding output quality.