One of the hardest things for me to explain is why you can’t fit the entire image when ordering different print sizes. Hopefully this will clarify this issue.
The cameras we use shoot at an aspect ratio of 2:3 (the same as most cameras) this means that for every 2 units an image is wide, it is 3 units long. Certain print sizes including the most popular 4×6 fit this aspect ratio perfectly. However, some sizes don’t fit so nicely (e.g. 5×7, 8×10, 11×14). Thus, cropping is necessary. Below are examples of the 3 most common sizes and how the image is affected to fit them.