Question

$\text{Praveen}$ used his telescope to observe some stars in the night sky. But the image of the stars appears to have an error, as shown below in the $\text{Defective}$ picture.

What is the name of the error in the image?

• A. Broken lens
• B. Spherical aberration
• C. Chromatic aberration
• D. Improper lens placement

Answer 1

The correct option is C Chromatic aberration

The defect with $\text{Praveen}$'s telescope is chromatic aberration, also known as chromatic distortion. It occurs when the lens cannot focus all of the colours of the light coming from the source at one point. Due to this, rings of colours (usually red, blue, and yellow) appear along the boundaries that separate the dark and bright parts of the image.