The Tamron 18-200mm f/3.5-6.3 AF XR Di-II LD Asph. (IF) Macro Lens is the first all-in-one zoom lens to achieve wide-angle-to-long telephoto coverage (28-300mm equivalent) along with outstanding imaging performance, it's still the world's lightest, most compact 11.1X zoom lens in its class. Ready for virtually any photographic opportunity -family events, distant wildlife and sports action, compelling close-ups of the kids -it does it all without having to change lenses.
Advanced Tamron technology -special XR and LD glass, Hybrid Aspherics, and Internal Focusing -is what makes all this possible in a dramatically downsized package. Cutting-edge internal and external multi-coating assures flare-free pictures even under challenging conditions. With specs like this no wonder it's Tamron's most popular lens.
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.