I have and have used a Sunpak auto DX12R for a number of years with no problems. Another approach would be a Manfrotto macro bracket flash #3278. You could set the arms at different angles for different effects or at 45o for even shadowless lighting especially with reflective subjects which tend to show the circle of the ringflash. It would work with most any flash and probably all you would need would be a couple of cheapo units and appropriate pc cord or a small slave.

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