Full-frame cameras have a large, light-sensitive full-frame image sensor. Because lots of light hits the sensor, you can take clear photos in low light. If you use a lens with a large maximum aperture, you can take photos with a shallow depth of field thanks to the full-frame sensor. You can isolate the subject from the background this way, for example. What the best full-frame camera is, depends on your usage situation. Choose a full-frame mirrorless camera for photos and videos of the highest quality.