Below is a scene I shot with the Sony Alpha 100 yesterday through the ISO range from 100 to 1600. On the follow-ups to this post are 1:1 crops of the centre of the frame for evaluating noise and grain characteristics.
Remember, this is a fairly unscientific exercise and only designed to give you a basic feel for the noise qualities of the camera.
The camera was set to normal programmed auto exposure, with standard segmented matrix metering mode. The standard 18-70mm kit lens was used. No exposure bias, tonal adjustments or sharpening have been applied.
Ian