Tamron 28-75mm F/2.8 Overview
Blending a sleek form-factor with a versatile working range, the 28-75mm f/2.8 Di III RXD from Tamron is a full-frame-compatible lens for Sony E-mount mirrorless cameras. Spanning wide-angle to portrait-length, a constant f/2.8 maximum aperture complements this range and affords increased control over depth of field along with enhanced low-light performance. The optical design incorporates a series of low dispersion and aspherical elements, which produce a highly corrected image with reduced spherical and chromatic aberrations for improved sharpness and clarity. Elements also feature Tamron's BBAR coating, which suppresses flare and ghosting for greater contrast and color fidelity when working in backlit and harsh lighting conditions. Benefitting the optical design is an RXD stepping motor, which enables quick, near-silent autofocus performance to suit stills and video, along with full-time manual focus override and a minimum focusing distance of 7.5". Suiting this lens's use in harsh climates, it also sports a moisture-resistant construction along with a fluorine-coated front element to protect against fingerprints and smudging.
- Versatile standard zoom is designed for full-frame Sony E-mount mirrorless cameras, however can also be used with APS-C models where it will provide a 42-112.5mm equivalent focal length range.
- Bright constant f/2.8 maximum aperture affords consistent brightness throughout the zoom range and offers improved control over depth of field.
- One XLD (eXtra Low Dispersion) element and one LD (Low Dispersion) element greatly reduce color fringing and chromatic aberrations throughout the zoom range in order to realize improved clarity and color accuracy.
- Two hybrid aspherical elements and one molded glass aspherical element minimize distortions and spherical aberrations in order to produce greater sharpness and accurate rendering.
- BBAR (Broad-Band Anti-Reflection) Coating has been applied to individual elements in order to suppress internal reflections, flare, and ghosting to achieve greater contrast and color fidelity when working in strong lighting conditions.
- RXD (Rapid eXtra-silent stepping Drive) autofocus motor delivers impressively quiet, quick, and smooth focusing performance to suit both stills and video applications. This focusing system also offers a minimum focusing distance of just 7.5"and a 1:2.9 maximum magnification for working with close-up subjects. Full-time manual focus override is also possible and it is compatible with Sony's Direct Manual Focus function or fine-tuned manual control.
- A moisture-resistant construction benefits this lens' use in inclement conditions, and a fluorine coating has also been applied to the front lens element to protect against dust, dirt, and smearing.
- Rounded nine-blade diaphragm contributes to a pleasing bokeh quality.