The ideal macro lens for clinical photography should have a focal length between 85mm & 105mm. This allows a suitable working distance between the lens and subject for close up work and gives a correct perspective for facial views. The latest, Tamron 90mm; Canon 100mm, Nikon and Sigma 105mm lenses all employ optical stabilisation. These lenses are considerably more expensive than the earlier non stabilised lenses. However at the moment both Canon & Tamron are continuing production of the non stabilised lenses which are totally adequate for clinical use as the brevity of the electronic flash obviates the need for stabilisation.