Covering a versatile wide-angle range, the atx-i 17-35mm f/4 FF, from Tokina, is an ultra-wide zoom that is well-suited for a variety of subjects, ranging from landscape to architecture to astrophotography. An advanced optical design incorporates a series of aspherical and low dispersion elements, which suppress a variety of aberrations for improved sharpness and clarity. Individual elements are also multi-coated to resist flare and ghosting for greater contrast and color accuracy when working in bright or backlit conditions. Complementing the optics, this lens features a One-Touch Focus Clutch Mechanism for fast changing between AF and MF settings, and an internal focusing design is used for responsive focusing performance.
- Wide-angle zoom is designed for full-frame DSLR cameras, however can also be used with APS-C models where it provides a 27.2-56mm equivalent focal length range.
- Constant f/4 maximum aperture affords consistent brightness throughout the zoom range and suits working in available lighting conditions.
- Three aspherical elements, including one glass-molded element and two P-MO aspherical elements, help control spherical aberrations and distortions for sharper, more accurate rendering.
- Three SD (super-low dispersion) elements control color fringing and chromatic aberrations throughout the zoom range for greater clarity and color accuracy.
- Anti-reflective multi-layer coated elements suppress flare and ghosting for improved contrast and color accuracy when working in strong lighting conditions.
- Silent-Drive focusing Motor (SD-M) pairs with a GMR sensor and an internal focusing design to achieve fast, responsive, and precise performance.
- One-Touch Focus Clutch Mechanism avails quick switching between autofocus and manual focus settings by either pushing or pulling the focus ring. When set to manual, focus response is especially smooth and benefitted by hard stops at the ends of the focusing range.
- Weather-sealed lens mount suits working in inclement conditions and resists moisture ingress.
- Nine-blade diaphragm contributes to a smooth bokeh quality.
- Included lens hood blocks stray light from causing flare and also offers some physical protection the lens.