Achromatic Refracting Telescopes: The Lens to Correct Chromatic Aberration
The invention of the telescope was one of the key inventions that allowed us to really begin to study space in detail. Even though a basic telescope can seem like a relatively simple object, they were actually only invented relatively recently. In fact, the evidence of the earliest concept of the modern telescope dates back to the early 1600’s – less than 500 years ago. In this post, we are going to take a look at one of the earlier telescope types, the achromatic telescope.
The achromatic telescope was first invented by a man named Chester Moore Hall in the year 1733. Chester Moore Hall was a lawyer from England with an interest in lenses and their potential uses. While the achromatic telescope was not the first type of telescope made, it was a type of telescope known as a refracting telescope, the same class as the first telescope made. Refracting telescopes manipulate light using lenses to create an enhanced image of distant objects.
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 telescopes were an improvement on the basic refracting telescope because the achromatic lens would focus and correct these color distortions, producing a chromatically correct image.