Pentax Optio X70 Samples

Below are sample crops from an indoor photograph of a book-spine at each of the Pentax X70's ISO settings. A crop from the Fujifilm Finepix S100FS
Fujifilm Finepix S100FS at the same ISO setting is shown next to each crop from the X70. 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. The last few crops are of lower resolution because of camera limits.

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.

Pentax Optio X70	Fuji Finepix S100FS
ISO 50 - 2.5s F5.6
ISO 100 - 1.3s F5.6	ISO 100 - 1.4s F5.6
ISO 200 - 0.6s F5.6	ISO 200 - 0.71s F5.6
ISO 400 - 1/3s F5.6	ISO 400 - 1/3s F5.6
ISO 800 - 1/6s F5.6	ISO 800 - 1/5s F5.6
ISO 1600 - 1/13s F5.6	ISO 1600 - 1/10s F5.6
ISO 3200 - 1/25s F5.6	ISO 3200 - 1/20s F5.6
ISO 6400 - 1/50s F5.6	ISO 6400 - 1/42s F3.5
The Pentax Optio X70 produces very usable ISO 50 to 100 shots. The ISO 200 shot has just a little more noise but nothing to be alarmed about. ISO 400 clearly shows increased noise and a color-shift, still it could be usable for a small print. Anything above ISO 400 should not be considered useful, noise and softness are high and so is the color-shift. Next to the X70, the Fuji S100FS really shines, note how the Fuji's ISO 400 crop looks similar than the X70's ISO 50, a 2 1/2 stop disadvantage for the Pentax Optio X70.