JJC Tripod TR 3 (Canon) The JJC Tripod TR 3 is a tripod mount for the Canon EF 100mm f/2.8L Macro IS USM lens. Compared to its predecessor, the TR 3 tripod nacelle is provided with a better closure by means of a screw button. By mounting your equipment on a tripod with a tripod nacelle, you shift the centre of gravity and relieve the burden on the lens mount of your camera. This is very important when working with heavy lenses.