Tokina's updated ultra-wide f/2.8 for APS-C — the atx-i 11-20mm with improved coatings.
The Tokina atx-i 11-20mm f/2.8 CF was released in 2015 as an evolution of the legendary AT-X 11-16mm f/2.8. It extends the zoom range to 20mm while maintaining the constant f/2.8 aperture that made the original so popular. The atx-i designation indicates updated coatings and the CF denotes the one-touch focus clutch mechanism.
Optical performance is very good. Sharpness is excellent in the centre from f/2.8 with good corners by f/4. The extended 11-20mm range provides more versatility than the 11-16mm without sacrificing the constant f/2.8 advantage. Updated atx-i coatings improve flare resistance. Excellent for astrophotography and low-light wide-angle work on APS-C bodies.
Canon EF-S mount in this listing — also available in Nikon F DX. Filter thread is 82mm — large for an APS-C ultra-wide. Weight is approximately 560 grams. Build quality is solid with Tokina's metal construction and the signature focus clutch for instant AF/MF switching. No image stabilisation.
Available on the used market at reasonable prices. Check the focus clutch mechanism and AF accuracy. The extended 20mm telephoto end (30mm equivalent) makes this more versatile than the 11-16mm predecessor. The constant f/2.8 remains the key selling point. An outstanding ultra-wide for APS-C astrophotography and landscape.