DIY Macro Lighting LED Ring: "If you're gonna try this at home (which you definitely should) note that the
parts I used were selected specifically for my camera and lens (Canon EOS450D + Canon EF-S 18-55mm f/3.5-5.6 IS), i.e. the inside diameter of the lighting ring needed to be greater than the 58mm diameter of the lens. If you’re having a go at this you may need to think ahead and do a bit of calculating, as the LED rings are available in several sizes."
