The 12-24 f/4 is based on an optical formula patented by Tokina.

All other lenses for which there is a Tokina version and a Pentax one (10-17mm f/3.5-4.5 fish-eye, 16-50mm f/2.8, 35mm f/2.8 macro, 50mm f/2.8 macro, 50-135mm f/2.8, 100mm f/2.8 macro and I might have forgotten some) are based on optical formulas patented by Pentax:

- 10-17mm f/3.5-4.5 fish-eye: patent JP-2007-94371, filed on June 12, 2006 (inventor:Jun Hirakawa), granted in 2007
- 16-50mm f/2.8: patent JP-2007-127989, filed in November 2005, granted in May 2007
- 35mm f/2.8 macro: patent JP-2008-257088, filed on April 9, 2007 by Hoya (inventor: Kato Koji), granted in 2008
- 50-135mm f/2.8: patent JP-2007-212830, filed on February 10, 2006, granted in 2007.
- 50 mm and
- 100mm f/2.8 macro are based on much older designs patented in the '80s, first used for the F series in 1987-1988.