Tamron USA, Inc. has announced the delivery date of the anticipated 28-300mm F/3.5-6.3 Di VC PZD (Model A010), an advanced new All-In-One™ zoom lens for full-frame DSLR cameras. The lens will be available in the U.S. in both Canon and Nikon mount (Sony mount availability to be announced) on June 26, 2014 at $849.

Since the launch in 1992 of the 28-200mm (Model 71D) high-power zoom lens - which featured a revolutionary compact, lightweight design - Tamron has been continually expanding its portfolio of world class optics to benefit consumers. Having revolutionized the optical design of the previous 28-300mm (Model A20), Tamron developed a powerful new, high-power zoom lens for full-frame DSLR cameras that enhances image quality and incorporates the PZD (Piezo Drive)-a standing-wave ultrasonic motor system optimized for swift, quiet AF-and the acclaimed VC (Vibration Compensation) mechanism in an amazingly compact configuration.

Featuring a new, sophisticated external finish, this lens complements the performance and style of full-frame DSLRs, while delivering the practical advantages of an All-In-One™ zoom lens.

1. State-of-the-art optical design technology delivers superior image quality
   The advanced optical construction of this lens includes four elements of LD (Low Dispersion) glass, three Molded-Glass Aspherical elements, one Hybrid Aspherical element, one XR (Extra Refractive Index) glass element, and one element of UXR (Ultra-Extra Refractive Index) glass, which has greater refractive index than XR. The full use of specialized glass elements in its design contributes to making this outstanding lens as compact and lightweight as possible, while minimizing aberrations, resulting in superior image quality. Particularly impressive is the thorough compensation of chromatic aberrations at the telephoto end, yielding images of enhanced clarity and crispness.
2. Focus on portability - The lens is now even smaller and lighter
   In addition to state-of-the-art optical design that facilitates downsizing of the lens body, the mechanical design, which incorporates a highly sophisticated multi-stack-cam layout that takes up far less space, and PZD (Piezo Drive), an autofocus drive system with a simpler, more compact structure, has made it possible to reduce the overall dimensions of this lens compared to the existing Tamron 28-300mm (Model A20). These technologies are the fruit of Tamron’s more than 20 years of research and development in the high-power zoom lens field.
3. Advanced anti-reflection coating
   The application of BBAR (Broad-Band Anti-Reflection) coatings for suppressing reflections on lens element surfaces minimizes unwanted flare and ghosting to deliver sharp, crisp, high-contrast images.
4. Upgraded cosmetic design – Elegant tungsten silver brand ring
   Tamron has upgraded the cosmetic design and finish of this lens to create a more sophisticated, high-end look in keeping with the demands of discerning full-frame DSLR users. Employing a sophisticated linear pattern rubber grip on the zoom and focus rings and an elegant tungsten silver name-brand ring, this newly designed model accentuates its visceral presence with understated elegance and class.
5. PZD (Piezo Drive) delivers faster, quieter autofocus action
   The PZD (Piezo Drive)*¹, a standing-wave ultrasonic motor system, delivers faster, quieter, more precise action when the autofocus is engaged. The full-time manual focus system is easy and intuitive, enabling quick and convenient manual focus at any time.
6. VC (Vibration Compensation)
   Tamron’s acclaimed VC (Vibration Compensation)² mechanism reduces image blur caused by camera shake to deliver significantly sharper images even when shooting handheld.
7. Circular diaphragm facilitates achieving spectacular blur effects
   Using a circular diaphragm*4, this lens achieves spectacular background blur effects that enable creative use of depth of field.
8. Moisture-resistant construction for outdoor shooting
   Moisture-resistant construction helps prevent moisture from penetrating the lens.

28mm

300mm

Superzoom lenses like this offer a versatile, compact option which is great for travel, or simply for when a large zoom range is convenient. This lens adds a decent vibration compensation system, resistance to dust and moisture and fast focusing to allow this lens to be used in a wide range of shooting scenarios, further increasing the convenience on offer.

http://www.ephotozine.com/article/tamron-28-300mm-f-3-5-6-3-di-vc-pzd-lens-review-26263

Its sharpness is pretty good considering what the lens is trying to achieve, particularly at the wider-angle settings. It never hurts to stop the lens down, but the usable aperture range is actually quite broad at most focal lengths. This means that in the sharpness department, you're not paying too high a price for the convenience of having a single lens to cover such a vast range of focal lengths.

http://www.photographyblog.com/reviews/tamron_28_300mm_f_3_5_6_3_di_vc_pzd_review/