A photographer told me a story about a lens maker that prized Ontario sand over all others. This sand, the photographer told me, gave the glass a golden glow. The subjects in films and photographs where these lenses WERE employed also look special.I bought a Tamron lens from the 1980s. You can count the elements by counting the refractions in these photos. You can even ascertain the groups and the spaces between them. 14 opportunities to enhance that golden glow. I don't know if Tamron uses Ontario sand, they should. I'm not sure that Ontario sand mine is still open.