I thought I understood the cropping effect and apparent impact of smaller sensors with, for instance, a crop factor of 1.6. However I have just purchased a 5DS R and cannot understand the difference between cropping at the point of taking the picture, compared to cropping in post production editing. Presumably there is a reason for the in camera cropping, but I don't understand why it is helpful and must be missing something. So a short article explaining this would be helpful. Thank you.