The camera response functions are saved in the “Library/Preferences/Photosphere” preferences file relative to your home directory on the Mac. I don’t remember where it gets put under Windows. The data is towards the end of the file, and looks like this:
CameraResponses = {
Make|Model|Version|Red|Green|Blue
"OLYMPUS OPTICAL CO.,LTD"|"E-10"|"42-0120"|{6.779350e-03,5.516785e-02,1.459309e+00,-2.929798e+00,2.408542e+00}|{6.390592e-03,8.606410e-02,1.246319e+00,-2.558258e+00,2.219484e+00}|{9.248151e-03,-9.216650e-03,1.786828e+00,-3.596076e+00,2.809217e+00}
"OLYMPUS OPTICAL CO.,LTD"|"C3030Z"|"v351u-76"|{3.396002e-03,3.315698e-01,-6.014519e-01,1.266486e+00}|{-4.601155e-03,3.578716e-01,-6.034859e-01,1.250215e+00}|{-7.762327e-03,4.018562e-01,-7.067782e-01,1.312684e+00}
} // CameraResponses
Not all that easy to read, but the polynomial coefficients are listed for red, green, and blue channels, respectively for the named cameras. Coefficients go from constant to higher orders, so “{-7.762327e-03,4.018562e-01,-7.067782e-01,1.312684e+00}” above corresponds to:
resp(x) = -7.762327e-03 + 4.018562e-01x + -7.067782e-01xx + 1.312684e+00xxx
Note that this order is reversed from that in hdrgen’s response curve file, and the order of the fit is implied by the number of coefficients (e.g., 4 coefficients == 3rd order polynomial).
Hope this helps!
-Greg