The Tokina 11-16 is always out of stock whenever I ask in shops, so I thought I would ask my question here. I've searched the forum already but found no answer. I want to find out whether it will work with a clip in filter that fits behind the lens (like http://www.astronomik.com/en/eos_clip-filters.html )
The obvious problem is to make sure the rear element doesn't move so far back that it touches the filter. I've done experiments with a 10-22 lens and its rear element extends behind the metal EF mount at 10mm and is just over half an inch (1.5 cm) inside the lens (below the metal EF mount) at 22mm. It seems to work better the further away the element is from the filter... too close and you get distorted corners.
So, can anyone describe the range of movement of the rear element of the Tokina 11-16, with respect to the back edge of the metal EF mount? How far inside the lens is the element at 11mm and 16mm, and which focal length is the element most inside the lens?
Thanks in advance for any help,