Hi Neville, I'm not sure about photography-related selenium but I have read in the Immune Restoration Handbook that organically bound selenium, such as that found in brazil nuts, at approximately 100 mcg./nut is more easily assimilated and nontoxic, even in relatively in high doses, compared to some other forms of the supplement. The same applies to the selenium found in high-selenium yeast supplements as well as in high-selenium mustard greens. For more details you could check the book:
http://www.keephopealive.org/khaads.html I hope this helps, Peter
