JJC Metal Tripod Collar Mount Ring for the Canon EF 70-200mm F/4L USM, EF 300mm F/4L USM and EF 400mm F/5.6L USM SLR Lenses by CowboyStudio
This CowboyStudio Tripod Collar Mount Ring is very lightweight and portable and would be a great addition to your studio. The TR-1   tripod mount ring replaces Canon Tripod Mount Ring A-2. This tripod ring mounts on the tripod and helps you fix and balance your lens. This   helps if your lens is heavy or if you have a long lens hanging off the front of camera.This tripod mount ring fits Canon EF 70-200mm f/4L USM, EF 300mm f/4L USM, and EF 400mm f/5.6L USM SLR lenses. This tripod mount ring   also has a fabric interior so it will not damage your lens. By adding a tripod collar to your lens you can achieve better balancing on a   tripod. In addition, rotating the camera will now be much easier and faster.Specifications:Fits Canon EF 70-200mm f/4L and EF 70-200mm f/4L IS lensesMade by metal with high qualityDirections:Attach the Canon 70-200mm lens to your camera body.Loosen the thumbscrew on the tripod collar, which goes around the camera's lens, to completely to open it up.Put the tripod collar around the lens where the depression to accommodate the collar is, between the two rotating black rings on the   lens.Tighten the tripod ring nearly all the way with the thumbscrew, making sure the fit is snug, but not so snug that the collar cannot   rotate.Rotate the tripod ring around so that the protruding foot is facing the bottom of the camera.Carefully align the foot of the tripod ring so that it is parallel with the bottom of the camera body.Tighten the thumbscrew you loosened earlier to make sure the lens, and thus the camera, does not rotate unnecessarily.Screw the tripod plate into the screw hole on the bottom of the foot of the tripod ring. Make sure you tighten it fully to avoid any   surprise drops or looseness when handling the camera.Reattach the tripod plate and attached camera to your tripod or monopod carefully, taking caution not to jostle or bump the lens   excessively. Most likely, the lens can take what you dish out, but the kinder you are to your equipment, the kinder it will be to you.Photograph as you normally would on a tripod or monopod. If you need to rotate the camera from landscape to portrait mode you can   loosen the thumbscrew on the tripod collar, grab the camera body, and turn. The lens will rotate within the tripod ring, allowing it to   move smoothly from one orientation to the other or anything in between. When you are finished rotating, tighten the tripod collar to lock   the camera lens and camera in place.