This Pentax AF160FC Ring Flash is a superb tool for macro photographers seeking clean and controlled light for a variety of close-up subjects.
Ringlights have a control box that sit atop the camera and a circular panel that fits on a lens like a hood. The controller allows for strength adjustment and P-TTL signals from the camera to be applied to the output of the flash.
Additionally, a modeling light helps preview the effect of the flash while simultaneously providing sufficient illumination for autofocus systems to operate. Adapter rings for 49mm, 52mm, 58mm, and 67mm threads are included.