Frank Rinehart
...that famed photographer of Native Americans Frank Rinehart used platinum emulsion instead of silver in photographs taken at the 1898 Omaha World's Fair to make the tonal range broader? 
...that famed photographer of  <a class="mw-redirect mw-disambig" href="./Native_American" id="mwAx4" rel="mw:WikiLink" title="Native American">Native Americans</a> <b id="mwAx8"><a href="./Frank_Rinehart" id="mwAyA" rel="mw:WikiLink" title="Frank Rinehart">Frank Rinehart</a></b> used <a href="./Platinum" id="mwAyE" rel="mw:WikiLink" title="Platinum">platinum</a> <a href="./Photographic_film" id="mwAyI" rel="mw:WikiLink" title="Photographic film">emulsion</a> instead of <a href="./Silver" id="mwAyM" rel="mw:WikiLink" title="Silver">silver</a>  in <a href="./Photograph" id="mwAyQ" rel="mw:WikiLink" title="Photograph">photographs</a> taken at the 1898 <a href="./Trans-Mississippi_Exposition" id="mwAyU" rel="mw:WikiLink" title="Trans-Mississippi Exposition">Omaha World's Fair</a> to make the tonal range broader? <i id="mwAyY">(pictured: Hattie Tom, photograph by Frank Rinehart, 1898)</i>