Macro lenses are specially designed to minimise the focussing distance, allowing the photographer to get closer to the subject and so increase the reproduction ratio. There are a number of other techniques that can be used to help achieve the desired magnification without a dedicated lens (extension tubes, close-up filters, reversing rings), however, one of less often considered techniques is to use something that you probably already have in your kit bag: a telephoto lens.
Telephoto lenses offer extreme magnification but generally have much larger minimum focussing distances pushing the photographer further from the subject and so reducing the reproduction ratio. Some telephoto lenses, when combined with camera systems utilising smaller sensors, are able to offer 1:1 magnification (‘true macro’) however, typically, telephoto lenses are limited to close-up photography, at near-macro reproduction ratios.
Using a telephoto lens for this kind of work offers a couple of advantages over a dedicated macro lens that are a direct result of the large minimum focus distance. Because the working distance to the subject is in the region of 1 metre (compared to 15 – 30 cm of standard macro lenses) the risk of disturbing your subject as you compose your shot is much reduced. Also, given the extra distance between the camera and the subject, you are much less likely to cast a shadow over your subject and have a lot of freedom with the lighting you can employ to light the subject – both natural and flash.
A wonderful idea, I never thought about using a telephoto lens to use in Macro photography. Usually you just see telephoto lens as that lens you use when your on vacation, to capture things too far away. But I like the thought of macro photography.