Tokina's updated fast APS-C ultra-wide — 11-20mm f/2.8 with wider range than the 11-16mm.
The Tokina AT-X 11-20mm f/2.8 Pro DX is an APS-C ultra-wide zoom with constant f/2.8 aperture, providing approximately 17-31mm equivalent on APS-C format cameras. An evolution of the well-regarded AT-X 116 Pro DX design. Canon EF mount.
f/2.8 constant aperture. 11-20mm zoom range (approximately 17-31mm equivalent on APS-C). Pro DX construction. At approximately 560g. 82mm filter thread. Canon EF mount. Nikon F and other mounts also available.
The AT-X 11-20mm extends the wide end beyond the AT-X 116's 11mm minimum to add 20mm as the maximum — providing more versatile ultra-wide coverage than the fixed 11-16mm design. The constant f/2.8 is an advantage for interior and astrophotography on APS-C bodies. The 82mm filter thread is larger than the AT-X 116's 77mm.
On the used market the Tokina AT-X 11-20mm f/2.8 Pro DX Canon EF is an affordable constant-aperture ultra-wide for Canon APS-C DSLRs. Condition checks: 82mm front element for marks, f/2.8 aperture blade condition, zoom ring and focus ring smoothness. APS-C coverage only. Compatible with Canon RF via EF-RF adapter.