I really love taking macro (close up) shots with my iPhone 4S. I did notice, however, I can only get so close before the lens will blur the image or not achieve a focus. By placing my iPhone on a steady stack of thin hard cover books and then varying the amount of books, I was able to get results for specific lengths:
I would say that the last distance was probably overkill. According to my estimates it seems that a range of 2.75″ to 3.0″ is a good length for a well lit iPhone close up shot. Also, keep in mind that we seldom stay perfectly still when we photograph, so these ranges are good qualitative data. I’m eager to see if the iPhone 6 macro capabilities will prove better than the iPhone 4S and iPhone 5.