Time to readless than
Marelux Flash tube
Marelux has developed a new gadget for fellow underwater macro photographers; SOFT-Smart Optical Flash Tube, which can be mounted on a range of popular flashes.
This unit has a built-in focus light that automatically turns off when the flash goes off.
Light shape can be adjusted by a built-in aperture, which is controlled by an external dial. The focus point is 170mm from the end of the tube and the diameter is 2mm to 60mm.
Further information or reference: