This lens establishes a new benchmark as a standard lens, extending from a wide 28mm all the way to 105mm telephoto, all with a fast constant 2.8 maximum aperture. The use of four large diameter aspherical elements and three LD glass elements reduces various aberrations while minimizing the fall-off of light at the corners. Tamron's Integrated-Focusing Cam system, Internal Focusing system and Triple-Cam zoom system all combine to permit a body that at the 28mm zoom position is very compact, with excellent optical performance. Also, a new Anti-Slip-Mode mechanism is incorporated for the first time. Anti-Slip Mode- A new Tamron mechanism that prevents the lens barrel from sliding outward under its own weight.