Canon has just filed a new patent for EF 12-20mm F4 lens. This is an ultra wide-angle zoom lens covering from 12mm to 20mm and featuring the constant F4 aperture.
In February 2015, Canon released the Canon EF 11-24mm f/4L USM Lens (Amazon| B&H| Adorama| eBay). This ultra wide angle lens is “the king of ultra wide-angle lens“.
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