Panasonic Lumix DMC-FZ100 Samples

Below are sample crops from an indoor photograph taken at each of the Panasonic DMC-FZ100's ISO settings. A crop from the Fujifilm Finepix S100FS
Fujifilm Finepix S100FS at the same ISO setting is shown next to each one of the FZ100. Images below are all unmodified 100% crops from their respective cameras taken at the highest quality setting. ISO was set on camera, everything else was left on automatic.

These crops help determine which ISO settings can be acceptably used. 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.

Panasonic Lumix DMC-FZ100	Fuji Finepix S100FS
ISO 100	ISO 100
ISO 200	ISO 200
ISO 400	ISO 400
ISO 800	ISO 800
ISO 1600	ISO 1600
From the start, the Panasonic concedes a lead of 2-2½ stops to the S100FS, producing noisy images even at its base sensitivity of 100. Each stop further adds more noise. From ISO 400 onwards, softness takes over significantly reducing possible print sizes.	ISO 3200