Compact versus full-sized binoculars often comes down to a matter of personal preference. Full-sized binoculars typically have larger objective lenses, which transmit more light. However, they’re also heavier, harder to carry, and can be cumbersome when hiking. Compact binoculars are lighter, easier to carry and handy to drop in a jacket pocket when you’re not using them at the moment. However, they have smaller objective lenses, which don’t transmit as much light to your eyes. Consequently, they’re not going to be as easy to clearly see a small bird at a long distance, especially in low-light conditions. In the end, the better view you’ll get of your avian quarry makes full-sized binoculars the best choice for most, but not all, birdwatchers. If you have a friend with both full-sized and compact binoculars, ask if you can borrow them to determine which you prefer before making a purchase.