The achromatic telescope makes use of an achromatic lens to create a better image than the lenses used in the original refracting telescopes. Lenses that were typically used in refracting telescopes refracted light at different angles, depending on it’s wavelength (in other words, depending on its color). This caused the resulting image to have color distortion, producing an inaccurate image.
Achromatic Refracting Telescopes: The Lens to Correct Chromatic Aberration
