What trick is real and what is imaginary?
October 29, 2020 | Education
| The point at which, after passing through the collecting lens, a beam of light parallel to the main optical axis is focused is called the main focus of the lens. After passing a beam parallel to the main optical axis through the diffusing lens, the light appears to come from a point behind the lens, which is called the imaginary main focus of the diffusing lens.
