Photographic image enhancement by a gold-toning neutron-activation process
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorClarence D. Bond
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Abstract
A gold-toning neutron-activation process for intensifying or amplifying the ontrast in extremely weak images in photographic negatives where the exposure level may be as low as 1.5% of optimum. The method involves three main steps: (a) gold toning of the silver image on the negative; (b) neutron activation of the gold image to produce radioisotopes; and (c) transferring the image to an unexposed autoradiographic film as the ionizing radiation from the radioactive gold exposes the film to produce intensification of the contrast.
Claims3
A method of photographic image enhancement on a film for subsequent transfer of the images to another film comprising the steps of:
- immersing a developed photographic film containing silver grains dispersed in an emulsion including gelatin molecules in a toning solution of gold chloride and ammonium thiocyanate whereby gold simultaneously plates the silver grains and attaches to the gelatin molecules;
- washing the film in a complexing solution of ammonium thiocyanate for substantially removing the gold from the gelatin molecules;
- and
- exposing the film to neutron radiation for rendering the gold plating radioactive.
Dependencies are inferred from the claim text.