Optimized for close-up shooting, the SP 90mm f/2.8 Di Macro 1:1 USD Lens from Tamron is a short telephoto prime designed for full-frame Sony A-mount DSLRs. Offering a life-size maximum magnification ratio of 1:1, this lens benefits working with small and nearby subjects and employs a Floating System for maintained image quality throughout the 11.8" to infinity focusing range. One Low Dispersion and two Extra Low Dispersion glass elements are incorporated into the optical design to minimize chromatic aberrations and color fringing for clean, consistent sharpness and clarity throughout the magnification range. BBAR and eBAND coatings have also been applied to minimize flare and ghosting for increased contrast when working in strong lighting conditions, and a rounded nine-blade diaphragm contributes to a pleasing bokeh quality to benefit shallow depth of field imagery. As an update to the classic 90mm macro, this enhanced version is well-suited to the high-resolution crop of DSLRs and blends timeless appeal and functionality with current imaging performance.
Supporting the imaging attributes is a precise, macro-optimized ring-type USD autofocus motor that provides fast and well-controlled focusing performance. A dedicated USD actuator is used to refine focusing precision at close distances and also compensates for small amounts of camera shake common to working at higher magnifications. Additionally, the focus motor affords full-time manual focus control for a greater range of adjustment capabilities. A moisture-resistant physical construction enables its use in trying environments and the front element has also received a fluorine coating to guard against smudges and moisture from affecting image quality. Additionally, this lens is compatible with the optional TAP-in Console for fine-tuning focusing performance and updating the lens' firmware.