Let’s talk a bit about print sizes!
Say you have an amazing photo you want to print out, you take it to a lab to have an enlargement but you realise afterwards you have lost a part of an arm or a leg. What happened? Where did that go? It’s all part of the aspect ratio.
Aspect ratio is the relationship of an image’s width to height, or its proportions. The aspect ratio for digital DSLR’s is normally 3:2. This is the equivalent of a small 4″x6″ but if you start sizing up to 5×7 or 8×10 you’ll lose something.
I personally like 8×10 size because it gives a more square look at the image (and I LOVE square) but you have to be aware that you will always lose a few inches because the ratio is 5:4.
To give you a better idea and visualize the cropping result I put together a guide with some popular sizes.
Hope this might be useful.