GH3 = attempt at Photographic Dynamic Range

If you want more input for the purpose of diagnosing how things actually work, it would be helpful if you could upload two more series:

1. Black-frame shots, one at each major ISO. Use highest shutter speed.

2. A series where you shoot a target other than your computer screen (a white wall or something like that) at each major ISO using the same aperture and shutter speed all the way. Make sure the chosen aperture and speed are such that there will be no raw-file clipping at any ISO. The reason for this request is that it's a bit tricky to judge how the camera reacts to ISO increases in shots of a computer screen like those you posted, especially since the shutter speeds used are higher than the screen refresh rate.