heliochromy การใช้

• In 1856, Hill wrote " A Treatise on Heliochromy ", a book that promised to reveal his secrets at last.
• Borrowing terms previously introduced in France, Hill called his process " heliochromy " and the photographs that it produced " heliochromes ", but by analogy to the naming of the then-current daguerreotype process after its inventor Louis Daguerre, Hill's color photographs were soon being called " Hillotypes ".