Addition of a limited amount of the non-radioactive thiourea in the radioactivating solution was effective in improving the general quality of the autoradiographically intensified image. The use of a radioactivating solution of 0.32 mCi/mg of sulfur-35 thiourea, containing a total of 2.02 X 10_-5 mole of thiourea, gave a characteristic curve that approximated that of a normal exposure. However, an attempt at proportional conversion of the image silver of the underexposed image to silver sulfide resulted in a degraded autoradiographic image with saturation density, gamma, and resolution (c/mm) less than that of the underexposed image. Autoradiography has been used to obtain intensified copies of badly faded historical photographs. The advisability of its use has not been determined. A variety of factors needs to be considered before autoradiography is used to treat a photograph.