Hello there and Happy New Year! Here’s to a wonderful year full of great photography! Now, let’s talk cropping ratios and dimensions! You will find this post extremely useful if you ever plan to enlarge your photos. Think of wide-screen movies versus full-screen movies. The wide-screen ratio is more narrow from top to bottom and wide from side to side. The full-screen ratio is a bit taller, but not as wide. Similar differences exist in standard photo sizes.
Pretty much any point-and-shoot or DSLR (with the exception of a medium-format or large-format camera) shoots in the 4×6 ratio. This means that when you make a 4×6 print, it will look exactly the way it’s framed in-camera. But if you enlarge it to a 5×7, you can see that some of the height will get cropped off. With an 8×10, even more height is lost. So if you had something important at the very top or bottom of the frame, it would get cut out. And you can see the ratios of other common sizes in the diagram as well. In the 20×24 size, all of the pretty hanging lanterns get cut out of the image. This is definitely something to keep in mind while taking pictures. I usually try to frame my photo the way I want it, but then zoom out a bit to leave some extra cropping room. If you’ll be makig enlargements, that foresight will really pay off in the end!