Review on Flash X-Tender FX-4 Flash Output Booster for Nikon 💡 SB-600 and SB-800 Flashes with 300mm Lenses - Better Beamer by Lori Lawson

As promised, allows you to go further without loss. Unfortunately, it's very difficult to line it up correctly - too high and the bottom edge of the picture is too dark, too low and the top edge is dark. More precise adjustment is required. Before using it I have to calibrate it and adjust the strap half a dozen times to get it in the right position and then be very careful not to hit it. Even then there's a lot of vignetting, which isn't a big deal as you can either enjoy the vignette or crop it - just so you know.