These lenses provide a small front aperture. With this they can be used to take pictures also through small holes. This can be of great advantage in surveillance applications, as well as for inspecting goods. The small aperture results also in a larger focal depth, which means that pictures can be taken sharp over a quite wide range of distance.

A disadvantage is however the low amount of light, which can be collected by the lens. This can yield to long integration times or the necessity to use an external lighting.