The latest version of the venerable Tamron 90mm Macro, the Tamron 90mm F2.8 SP AF Di 1:1 Macro Lens is widely used by naturalists and other pros who need top imaging performance plus a longer lens-to-subject (working) distance to enable easier lighting and access to skittish subjects. Improved resolution, chromatic correction, and coatings make it a superb choice for full-frame or APS-C format SLRs.
Tamron's 90mm macro lens, often referred to as "the portrait macro" and loved by photographers all over the world, is now redesigned as a Di lens that is perfect for use with both film and digital cameras. The Digitally Integrated Design(Di), is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras. It inherited the same optical configuration of the previous generation lens but, the new version features a new optical design which is applied to its coated surfaces. The external design is improved and the focusing ring features an improved rubber pattern that fits comfortably in your hands. . The lens is recommended as an easy to use portrait lens for film cameras an as a telephoto macro on APS-C sized digital cameras. It provides them with a full-sized equivalent angle of view of 140mm. One can truly discover the smaller things in life without disturbing your subject.
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.