Reciprocity for Multigrade RCIV paper [update]

Here is a reciprocity curve for Multigrapde RCIV Paper. The formula comes from f/295 forums : http://www.f295.org/Pinholeforum/forum/Blah.pl?m-1252335783/. The author (banana_legs ) uses this formula :
t_s = t_c + 0.0009 * (t_c ^2.2304)

I transcribed it for pinhole assist and you can download it with this link.

Thank to the contributor of the discussion here for their interest.

12/11/2012 : link updated