Designed for optimum handling ease and portability (it weighs only 458g / 16.2oz), The Tamron 70-300MM f/4-5.6 DI LD AF Lens is ideal for handheld shooting with full-frame and APS-C format SLRs. Its unsurpassed close-focusing ability (down to 0.95m(3.1 feet) or 1:2 in macro mode) makes it perfect for nature and portrait photography.
This lens is a Di (Digitally Intergrated Design) type lens which uses an optical system with improved multi-coating designed to function with digital SLR cameras as well as film cameras. With Tamron's 70-300mm telephoto zoom lens, flipping a macro switch in the focal length range of 180mm to 300mm obtains a maximum magnification ratio of 1:2 at a minimum focus distance as short as 37.4", enabling close-up shots of flowers, insects, and other objects that normally require the use of a specially designed macro lens. Moreover, this is a zoom lens that casually offers the distant capture and foreshortening effect pleasures of the 300mm ultra-telephoto world. An advanced optical design which incorporates special LD glass is also a feature of this lens. The lens is 22% lighter and 4% shorter than other lenses in its class
This is the magnifying factor of a lens. Macro lenses will often be described by their “magnification factor”. A lens with a 1:1 magnification factor produces a projected image on the sensor which is the same as the subject.
The individual pieces of glass that form the overall optical construction. Most lenses have between four and eleven elements to bend the light rays to ensure a perfectly formed image appears on the light sensitive surface, such as a film or CCD. The elements are arranged in groups and may be seen in specification sheets as, for example, 6 elements in 4 groups. That configuration may have two single elements and the other four grouped in pairs.
A lens with a 1:1 magnification factor produces a projected image on the sensor which is the same as the subject. A 1:1 magnification factor is usually considered the minimum for a lens to be described as a “macro” lens. Specialist macro lenses are often 1:3 or even 1:10 magnification factors, meaning that 1mm across the subject becomes 3mm or 10mm when projected onto the sensor, thus 3 or 10 times magnification.