With wildlife, many photographers try to get closer and closer to completely fill the frame with whatever animal they are photographing. Beyond the potential dangers to yourself and stress to the creature, it also limits how you can display your image.
While the welfare of yourself and your subject are the primary concern, the desire to get “up close and personal” can also keep you from making your best images of that creature.
Every image capture device or display can be described as having an “aspect ratio;” cameras, monitors, prints, etc. This is a comparison of image width to the height, written in ratio form. So think of our most common one, the 3:2 ratio, the standard used by 35mm film cameras and most DSLRs on the market. The width of the camera’s sensor is 1.5 times larger than its height. For simplification, if it the sensor was an inch tall it would be 1.5 inches wide. So all the images created and displayed use this ratio as well. Prints, without cropping, will be 4×6, 8×12, 20×30, etc.
As cameras have evolved, smartphones have appeared, and our monitors have gotten bigger and better, a number of other aspect ratios have become more common — 4:3, 16:9, etc. All of these describe the same thing — a ratio of width to height.
Why this matters?
Think of an 8×10″ print. If the image coming out of your camera is in a 3:2 ratio, it naturally prints as an 8×12″ image. So printing an 8″ means you have to cut an inch off each side. If you have shot too tight, you can’t do this crop without “clipping” the animal, possibly losing some of the most important parts of your image.
I’m not suggesting you sacrifice your composition or that you should rely on crops instead of getting it right in the camera. However, shooting a little looser will allow you to use your image in more ways while still giving your wild animals room to be alive in the frame.