A megascope is an instrument that spins around the diamond and uses a laser to measure every single facet and proportion of the diamond to incredibly high resolution (one micron, 0.001mm). Color and clarity are very easy to measure by a trained gemologist and is not rocket science- you simply compare one diamond to another. But cut is completely different. It is the least understood even by people in the jewelery trade, and is something often left to the engineers; mathematicians and statisticians that tell the Gemological laboratories what proportions a diamond should be cut to, to get maximum fire from a diamond.