I'm planning on buying a Canon 5D. One primary subject will be coins. In considering the Canon MP-E 65MM 1-5x lens for this. The 5x magnification will be usefull for getting the small features of a coin. Im not clear on all the features of this lens. Will I be able to photograph larger coins, or will the lens not support magnifications of less than 1x? Would it be more practical to use the Canon EF 100MM lens. I could use closeup filters for getting the small details.