90mm 1:1 Di macro zoom lens. The Tamron SP designation is reserved for lenses developed with special emphasis on extraordinary photographic performance. Engineers are free to innovate in an uncommon atmosphere where optical performance comes before price, resulting in lenses that satisfy the demands of discerning photographers. The SP 90mm F/2.8 Di enjoys enviable DNA from Tamron's original SP 90mm F/2.8, further refined for the demands of high-resolution digital imaging. Extraordinary 1:1 (life-size) close up capacity, combined with what many consider an ideal portraiture focal length (when used on full-frame DSLR or 35mm SLR cameras) this prime optic was nicknamed the portrait macro. Equally at home on APS-C DSLRs, rendering a picture angle equivalent of the 140mm lens on a full-frame DSLR or 35mm SLR camera, photographers appreciate the resulting increase in front element-to-subject distance and close-up photography. In addition, this 135mm-like picture angle is well-suited for environmental portraiture. Extraordinary sharpness, striking contrast and a remarkable absence of distortion combine to produce images of exceptional caliber.