Luckily, our local pro photo store rents a full line of Nikon and Canon lenses so I was able to give Canon's MP-E 65mm f2.8 1-5x Macro a spin last weekend.
Before renting it, I read that this 1-5x Variable lens could fill a frame with a single grain of rice. When I picked the lens up from the shop, the guy told me it can photograph grains of salt. Could it possibly be true?