Product Features:Ergonomics and exterior designThe ne.w Tokina opera 16-28mm F2.8 FF has been designed to provide the photographer comfort and confidence during the shooting. The lens comes in a sophisticated, gorgeous but yet simple and slim housing with well balanced zoom and focus ring arrangement. Opera 16-28mm F2.8 FF is designed to fit top class DSLR cameras and by no means meant to be light-weight and compact. It is the lens that, once held in hand, makes the photographer realise himself involved into the shooting process and is suggested for those who are serious about photography.Fast and accurate AFThe lens uses a Silent Drive module that allows the lens to focus speedily and quietly. This DC motor, coupled with a ne.w GMR magnetic AF sensor, works together to increase AF speed and accuracy.Overview:One-Touch Focus Clutch MechanismTokina's exclusive One-Touch Focus Clutch Mechanism allows the photographer to switch between AF and MF simply by snapping the focus ring forward for AF and back toward the lens mount for manual focusing.About opera SeriesTokina opera represents a series of next generation, premium full-frame lenses for high-end DSLR cameras. The ne.w series perfectly matches recent high-resolution full-frame DSLR cameras that demand the highest quality optical designs. Built on the award winning heritage of Tokina's AT-X line, the ne.w opera series will of/er an ever-expanding, premium line of full-frame lenses that meet the growing demands of high-performance DSLR cameras.In modern society the word 'opera' is commonly used to indicate stage art works that combine drama, music and dance. In Italian, it means work or work of art. As an omitted art genre definition, opera comes from 'opera musicale', which means a piece of music work. In Latin, opera comes from 'opus' that is still used in contemporary language meaning 'great literary, artistic or intellectual work' (e.g. 'magnum opus', 'opera magna'). We chose the name opera for our ne.w premium full-frame DSLR lens series with the idea that it will help the photographer in creating real 'works of art'.Tokina Opera 16-28mm F2.8 FFOpera 16-28mm F2.8 FF is a super wide zoom lens featuring super wide angle at 16mm and traditional wide angle at 28mm that stands at the border where the standard zoom angle range begins, thus providing the photographer practically full wide angle coverage with only one lens.Super wide angle, superior resolving ability coupled with high contrast and beautiful bokeh rendering, fast f/2.8 constant aperture throughout the zoom range and accurate AF drive system make this lens attractive for photographers who specialise in landscape, interior architecture, street snap, documentary, environmental style portrait and night sky/time lapse photography genres.Optical performanceThe ne.w Tokina opera 16-28mm F2.8 FF incorporates a complex optical design with 15 elements in 13 groups, 3 of which are of aspherical type including large aspherical P-MO element and 3 are glass moulded Low-Dispersion (SD) elements for effective suppression of chromatic and spherical aberrations.This optical design performs just optimal resolution at the aperture wide open that greatly increases by stepping down to f/4 and narrower. To make the lens suitable for landscape shooting and BW photography, engineers made maximum efforts to realise high levels of contrast and rich colour gradation in the image.