Light field cameras have been extensively used in a variety of applications, thanks to their snapshot three-dimensional imaging capability. However, little is known regarding their pros and cons for a given application. Herein we report a fundamental comparison between two types of light field cameras-focused and unfocused. Our results indicate that the unfocused light field camera outperforms its focused counterpart in depth range and number of resolvable depth steps, while the focused light field camera has an edge in lateral resolution and reconstruction accuracy.