 Unfortunately, as time has passed, the silver of the photographs has faded, but the paint has not, so the portraits have an uneven, exaggerated, faded and sometimes splotchy look.It is thought that this is one reason why Collen's work in photography has not been recognised as it may have been if the portraits had remained intact.In the 1844-46 period, Collen interacted with inventor Francis Ronalds, Honorary Director of the Kew Observatory.