I tried to devise a simple test to show comparison images taken with various cameras. The idea behind the test is to use subjects which are widely available so that other people can redo the same test with a different camera, even if they live somewhere else on the planet.
Since the object is to test high iso noise, we need the following objects:
-some colour reference object, I chose to use the widely available X-rite chart.
-some objects with fine structures and muted colours. I chose to use banknotes, which have the perfect combination of features and are widely available. But please keep in mind that we do not want to counterfeit money and that photoshop includes a system that will jump at you if you crop a complete banknote image, so leave some part of the notes out when you crop the picture.
The reference objects are attached to a wall (just make sure they lay really flat), the camera has a standard 80mm lens, distance is 2.5 m, the scene is lit with daylight (a nearby window). I suppose a studio flash could also be used. The aperture is constant at f/11 (compromise between depth of field and diffraction) and I vary the shutter time (vary the flash output if you use flash). If I were to vary the aperture, lens sharpness would vary.
Exposure is measured with an incident light meter. If you use the built-in meter, compensate about +1ev, since you are mainly taking a picture of a white wall or use a grey card.
Attached is the resulting complete picture, just scaled down.