it has been designed around the best optics i have cooke speed panchro,leica noctilux,nikon noct imaging onto a 5d sensor size.
i took the best designs i could find realised most achromats are design for long and zoom lens so started from scratch again.
so although the tokina is the best of it's type in terms of light ray path my new ones have better correction hitting the film plane.
the quality of my glass is better and more exotic than the tokina and fully configured for the job.
no price at the moment but you can test it when i get time to machine a mount for it : )