I recently upgraded to a 5D mark iii camera from the rebel 4ti. I have the canon EF 50mm f1.8 II lens that I used on my rebel. From what I've read, I should be able to use it on my 5d mark iii since rs an EF lens, but the base is too small for the 5d body. Do I need an adapter? And yes, I know that the 50mm 1.4ii is a better lens, but for now if this will work, then I can make do for a little while.