Tamron 18-200mm F3.5-6.3 DI III VC Lens for Sony E-Mount

The first all-in-One Zoom For Sony APS-C E-Mount cameras by Tamron, its noteworthy 11x zoom guarantees greater shooting flexibility. With its maximum F/3.5-6.3 and minimum F/22-40 aperture, ø62 filter diameter, and internal focusing (IF) system, this lens promises quality images in different levels of lighting. The combination of VC (Vibration Compensation), with its fine-tuning stepping motor, and zoom lock system preserves the quality of whatever set-up you formulate. Chromatic and spherical aberrations are eliminated by its special low dispersion (LD) and hybrid aspherical glass elements, solidifying its photography performance. This is the choice lens for taking pictures while moving and/or from a large distance. It is compatible only with APS-C DSLR Cameras.

Product Features in Detail

Tamron Di III
Tamron Di III lenses are engineered specifically for mirrorless interchangeable-lens cameras with no internal mirror box or pentaprism, adopting an optical design that matches the characteristics of the digital camera. (Note: These lenses cannot be used with digital SLR cameras with built-in mirror box or conventional 35mm film SLR cameras).

VC (Vibration Compensation) 
Tamron’s conventional VC (Vibration Compensation) unit has a moving magnet system with heavy magnets in the vibration-compensating lens. However, the new VC mechanism adopts a lightweight moving coil system that reduces the load on the drive system. This allows the drive to be operated with smaller coils and magnets, reducing the weight and size for the entire VC unit. In addition, improvements to software and other elements of the VC mechanism used in the 18-200mm Di III VC have made the mechanism even quieter.

Stepping Motor
18-200mm Di III's autofocus mechanism uses a stepping motor that is an ideal match for the Contrast-detection AF system used in Sony’s NEX series cameras. The stepping motor’s actuator allows finely tuned control of angular rotation, and since it drives the focusing mechanism directly without an intermediate reduction gear, it also provides superbly quiet performance. You can count on this to enhance autofocus capability when shooting video. Furthermore, after adjusting with the AF mechanism, you can use the Direct Manual Focus (DMF) function for delicate adjustments to the image. In short, you can capture the scenes you want focused exactly as you want them every time

Low Dispersion (LD) Glass for Greater Lens Sharpness
Low dispersion (LD) glass elements in a lens help reduce chromatic aberration; the tendency of light of different colors to come to different points of focus at the image plane. Chromatic aberration reduces the sharpness of an image, but glass with an extremely low dispersion index, has less of a tendency to separate (defract) a ray of light into a rainbow of colors. This characteristic allows the lens designer to effectively compensate for chromatic aberration at the center of the field (on axis), a particular problem at long focal lengths (the telephoto end of the zoom range), and for lateral chromatic aberration (towards the edges of the field) that often occurs at short focal lengths (the wide-angle end of the zoom range.)

Hybrid Aspherical Elements Provide the Ultimate in Image Quality and Compactness
Tamron uses several hybrid aspherical lens elements in many lenses bearing the aspherical designation. These innovative optics allow us to achieve the ultimate in image quality, and at the same time produce lenses that offer remarkable zoom ranges in extraordinarily compact packages. By perfecting theses cutting-edge advances for series production, Tamron has advanced the state of optical design, and virtually eliminated spherical aberration and image distortion from the high-power-zoom series.Through the effective application of Hybrid Aspherical Technology, one lens element can take the place of multiple elements without compromising performance. This is what allows us to produce remarkably compact long-range lenses that deliver a uniformly high level of image quality at all focal lengths and apertures.

Internal Focusing (IF) System
Internal focusing (IF) provides numerous practical benefits to photographers including a non-rotating front filter ring that facilitates the positioning of polarizing and graduated filters, and more predictable handling because the lens length does not change during focusing. Even more important, Tamron’s Internal Focusing (IF) system provides a much closer minimum focusing distance (MFD) throughout its entire focusing range. In addition, IF improves optical performance by minimizing illumination loss at the corners of the image field, and helps to suppress other aberrations that become more troublesome at different focusing positions.

Zoom Lock (ZL) Feature
Another original Tamron mechanical engineering concept is the Zoom Lock (ZL), a simple convenience feature that prevents undesired extension of the lens barrel when carrying the camera/lens unit on a neck strap.

Sharpens edges by reducing 'colour fringing'
Chromatic aberration occurs when a lens element refracts different wavelengths of a ray of light – its rainbow colours – at very slightly different angles. This results in the 'colour fringing' that reduces the sharpness of an image. LD elements are made from special glass materials with extremely low dispersion indices (i.e. the refraction of a ray of light into rainbow colours is extremely narrow). Thus they effectively compensate for chromatic aberration at the centre of the field (on axis), a particular problem at long focal lengths (the telephoto end of the zoom range), and for lateral chromatic aberration (toward the edges of the field) that often occurs at short (wideangle) focal lengths.

More compact lenses with superior image quality
XR (Extra Refractive Index) glass can bend light rays at steeper angles, thereby decreasing the physical length of the lens while enhancing imaging performance by minimising optical aberrations. With its superior light-bending power, XR glass makes it possible to design a short-barrel lens with the same light-gathering ability (aperture value) as a long-barrel lens – even with a smaller lens diameter. By using this principle Tamron has been able to shorten the length of the entire optical system and produce lighter, more compact lenses of the same speed, and also to provide greater zoom ranges in lenses that are much more convenient to carry and hand-hold.

Far superior image quality – while reducing lens size and weight
Tamron uses several hybrid aspherical lens elements in its lenses bearing the Aspherical designation. The benefits are two-fold: first, their non-spherical shapes virtually eliminate spherical aberration and image distortion. Second, as one hybrid aspherical lens element can take the place of multiple elements without compromising performance, they allow the lens to be much more compact.