Advice on selecting best camera lens

Press, 26 December 1985, Page 15

Advice on selecting best camera lens

Camera lenses have improved markedly over the last few years, but some are much better than others. Dr Peter Harper, senior lecturer in the extension studies department of the University of Canterbury, has listed what he considers the best of the 35mm format lenses now available. Often the distinction between lenses is not so much in the qualities of the glass as in the design of the lens. Computers have enabled the designing of greatly-

improved (or often previously unattainable) lenses of certain focal lengths and apertures, while no corresponding breakthrough has yet occurred with others. A feature of the com-puter-designed lenses is the tendency to a reduction in the number of lens-elements (the individual lenses which make up the compound lens supplied). Formerly, the more elements a lens had the better it was likely to be, because the main aim' of

many elements was to reduce imperfections; but there is a new awareness that each element adds two faces to scatter light and thus degrade the image. While zoom ■. lenses r have also been improved greatly their performance is not as good as that of corresponding fixed-focus lenses, because of the need for additional elements to achieve the variation in focal length. Dr Harper, who conducts classes in wild-life photo-

graphy, lists the best of the new lenses as: 20mm f 2.8, 24mm f 2.8, 35mm f2, 55mm macro f 2.8, 105 mm and 105 mm macro f 2.5, 180 mm f 2.8, 200 mm f 4, and 300 mm f 4.5.

He does not recommend zoom lenses (apart from convenience in carrying), mirror lenses, 28mm lenses, lenses of greater than 300 mm focal length, or standard (50mm or 55mm) lenses, except in macro versions.