Our Video Lady, Melissa, has popped this on the blog desk with the note that it is a very good idea for videographers who are using DSLR cameras and want to mount a separate monitor screen or microphone. A still photographer might fancy mounting a flash unit at an odd angle to fire down on a macro subject. You could slip a doughnut over it in case you get hungry during the shoot.
The arm is 7" overall but you can also get them out to 11". The knob clamping the movement is smooth and positive - no creeping of the arm in operation. If you just need a particularly sturdy column up from the hot shoe, the articulated portion unscrews.
Best of all is the reasonable price: $49.95.
Magic arm. Melissa-approved.
