Field-test of Canon EF 100mm f/2.8 macro lens. Many Canon EF zoom lenses have a continuous macro function that lets you get closer to your subject. By using this feature, you can achieve magnification ratios of about 0.25X - roughly _ life-size - depending on the lens. This is a pleasingly affordable way of getting started with close-up photography since you can use these zoom lenses for much of your standard shooting as well. However, what if you wanted to shoot closer than what the zoom lenses are able to provide? There are a number of ways to achieve that; with the cheapest being add-on close-up lenses that screw into the filter thread at the front of many EF lenses. Or you can use an extension tube, like the Canon Extension Tube EF 12 or the Extension Tube EF 25. These extension tubes are accessories that can be mounted between your EF lenses and the EOS camera body. << Back to Main . 1 . 2 . 3 . 4 . 5 . 6 . 7 .