Originally posted by timstone why would they make a 10-16 when they've already got a 10-17?
Both Pentax and Tokina have the 12-24, with Pentax supporting the K mount. Its a constant f4 lens. It has a field of view of 100 to 60 degrees
Both Pentax and Tokina have the 10-17, with Pentax supporting the K mount. Its a f3.5-4.5, but more importantly a FishEye lens. It has a field of view of 180 to 99 degrees.
Tokina has a 11-16, for Canon and Nikon. Its a constant
f2.8 lens. It has a field of view of 104 to 82 degrees.
So the new Tokina lens is faster and a tad bit wider in the field of view. Physically from what I have read, its basically the same size and weight as the 12-24, and as indicated earlier, is based on the 12-24 design.
There is a huge difference between the 11-16 (and for that matter the 12-24) and the 10-17. The 11-16 is a regular rectilinear lens while the 10-17 is a fisheye. They are as different as night and day. The field of view is the give away on this, and just by looking at the produced images. The focal length of the fisheye belies its true capability.
hope that helps...