EF Lenses - Normal types or L-series? One of the questions that many EOS users always ask themselves is whether they should invest in the L-series of Canon EF lenses or choose the consumer-grade versions for their respective EOS cameras. The consumer-grade types, also popularly referred as the "prosumer" category, are those EF lenses that employ either the Micro Motor, DC Motor, Micro USM or Ring USM and do not utilize special optical glass like the grounded-&-polished aspherical and UD elements, or the artificially grown calcium fluorite crystal, which the L-series lenses have. A beginner/ amateur's EOS equipment lineup Advanced amateur /professionals' EOS equipment lineup However, this does not mean that the prosumer EF lenses are optically inferior to the L-series type. Since most of the L-series EF lenses are large aperture types including the zooms, the designs are therefore more complicated and the manufacturing costs are higher than what it takes to make the prosumer EF optics. The conventional EF zoom lenses are those employing the variable maximum aperture types, and depending on the grade, they either utilize polycarbonate or steel mounts and also use non-metal parts for the lens barrel and internal constructions, thereby further lowering their production costs. However, not all prosumer EF lenses are manufactured using the lower production cost methods as there are also those that are made with a higher degree of precision. These are usually the single focal length EF lenses employing the Ring USM and FT-M feature like the EF 20mm f/2.8 USM, EF 28mm f/1.8 USM, EF 85mm f/1.8 USM, EF 100mm f/2.0 USM and the EF 100mm f/2.8 Macro USM. Other single focal length lenses not utilizing the Ring USM but the older Arch Form Drive (AFD) such as the EF 24mm f/2.8 AFD, EF 28mm f/2.8 AFD, EF 35mm f/2.0 AFD, EF 50mm f/2.5 Compact Macro and the EF 135mm f/2.8 Soft Focus are also manufactured with high precision. While these prosumer lenses' barrels are made of glass-fiber reinforced materials, their internal parts are metal, enabling years of usage without wear and tear. Although none of the elements in these EF lenses are of the expensive materials like aspherical, UD, Super UD and Fluorite, they nevertheless comprise high refractive, aberrations-corrected optical glass. << Back to Main . 1 . 2 . 3 . 4 .