A piece of equipment that has a the right feel to it and which does the job. The narrow depth of field (on the EF100mm f/2.8L Macro IS USM) compels, in my view, a sturdy tripod with the extra tools (collar, and yet to buy a track for fine adjustment) to get the sharpest focus. Manual focus is, of course, the right mode to use. Very pleased with the purchase and for any one seriously interested in macro photography and spectacular results, this extension is a 'must'. There are cheaper extensions but the Canon is my choice.