Advanced optical technology
Specialised high-grade glass in the three LD elements, three Glass Molded Aspherical Lenses, one Hybrid Aspherical Lens and two XR (Extra Refractive Index) elements all contribute to the top-of-class image quality expected of a high-grade Tamron SP lens.
Extra Refractive Index
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.
XR glass is costlier than conventional glass but it yields enhanced optical power distribution, making the innovative XR lens designs possible.
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.
As a result, these innovative optics have played a crucial role in delivering uniformly high image quality across all apertures and focal lengths of extraordinarily compact ultra-zoom lenses.
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.
Although costly, LD glass materials result in clear, vivid image quality.
Attention-grabbing blur effects at wider apertures
Use depth of field more creatively with spectacular but natural-looking background blur.
The rounded outline diaphragm of the lens is retained even when stopped down to f/5.6. Blur highlights in a photo reflect the shape of the aperture, and they are a much more prominent feature at wider apertures. Especially in higher-speed lens, this important optical design element results in more attractive, natural-looking images.
Moisture resistance adds protection
Moisture-resistant body construction helps prevent water from penetrating the lens, making it well suited ideal for travel and shooting outdoors.
Flower-shaped hood is supplied with the lens to shield stray light
Included as a standard accessory, the flower-shaped hood matches the rectangular shape of the image sensor to most effectively block the interference of superfluous light rays entering from outside the borders of the image area, helping to ensure sharp, clear, flare-free images with crisp detail in the shadow areas.