Canon 5D Mark III ISO Series versus Sharpening
Just published in my review of the Canon 5D Mark III in DAP is a new ISO series from 50 to 25600 using my standard sharpening approach, which shows how hard one might have to work to deal with noise at ISO values 1600 on up.
I consider the practical limits of noise as where I have to alter my usual workflow, and to have to start dealing with noise by sharpening less or using black and white conversion or noise reduction, etc.
B&H Photo has the Canon 5D Mark III with 24-105mm f/4L zoom in stock at present.