Ring flash
When shooting at the close focusing distances required for macro photography, the lens barrel itself may well obstruct light from falling onto the subject, and combined with the narrow apertures required, can require an additional light source for a well-exposed shake-free image. But hotshoemounted flashguns, which sit above the camera body, are in the wrong position to light the subject properly.
That’s where ring flashes come in. They sit around the end of the macro lens barrel to provide an even distribution of light just a few inches away from the front element, and also require less power to light the subject well.