Researched
Achromatic Lens (Dollond)
John Dollond's lens of crown and flint glass (patent 1758) cancels colour fringes and makes sharp refracting telescopes and cameras possible.
Open in the interactive tree →Chester Moore Hall had built the first achromat around 1733, and Newton's study of dispersion had shown the problem. Achromatic lenses gave sharp images in telescopes, microscopes and, later, photography.
Prerequisites
Unlocks
- Fraunhofer: Lines & Gratings1814
- Photography1839Early cameras needed achromatic lenses to give sharp images