The tokina 12 28mm f4 af at x pro dx lens is an ultra wide angle lens designed for canon digital slrs with an aps c crop sensor this lens offers a constant f40 aperture thats ideal for capturing a wide variety of applications whilst the sd m silent drive module ensures autofocus is smooth and silent making it suitable for videography the lens is equipped with 14 elements in 12 groups and boasts a minimum focus distance of 25cm