What images do the eyepiece and objective lens of a microscope and telescope form respectively?
The objective of a microscope produces a magnified inverted real image, the eyepiece of a microscope produces a magnified upright virtual image, and the final image of the microscope is a magnified inverted virtual image; The objective of the telescope is an inverted reduced real image, the eyepiece of the telescope is an upright magnified virtual image, and the telescope ultimately forms an inverted magnified virtual image.
A telescope is an optical system that uses an objective lens and eyepiece to keep the incident parallel light beam parallel and emitted. According to the telescope principle, there are three types. The instrument that observes electromagnetic radiation from distant objects by collecting electromagnetic waves is called a radio telescope.
In daily life, telescopes mainly refer to optical telescopes. But in modern astronomy, astronomical telescopes include radio telescopes, infrared telescopes, X-ray and gamma ray telescopes. The concept of astronomical telescopes has further expanded to the fields of gravitational waves, cosmic rays, and dark matter.
A microscope is mainly composed of an eyepiece, objective lens, stage, and reflector. The eyepiece and objective are convex lenses with different focal lengths. The focal length of the objective convex lens is smaller than that of the eyepiece convex lens. The objective lens is equivalent to the lens of a projector. This object is inverted and magnified through an objective lens. The eyepiece is equivalent to a regular magnifying glass, which creates a magnified virtual image of the real image through the eyepiece.
Introduction to microscope objectives and eyepieces
objective lense
Various objective lenses can be used, but it is best to use achromatic lenses because their self fluorescence is extremely small and their light transmission performance (wavelength range) is suitable for fluorescence. Due to the fact that the fluorescence brightness of an image in the microscope field is directly proportional to the square of the aperture ratio of the objective lens and inversely proportional to its magnification, in order to improve the brightness of fluorescence images, an objective lens with a larger aperture ratio should be used. Especially at high magnification, its impact is very significant. Therefore, for specimens with insufficient fluorescence, an objective lens with a high aperture ratio should be used, combined with an eyepiece lens as low as possible (4 ×, 5 ×, 6.3 ×, etc.).
eyepiece
Low magnification eyepieces such as 5 × and 6.3 × are commonly used in fluorescence microscopes. In the past, single tube eyepieces were often used because their brightness was more than twice that of double tube eyepieces, but research fluorescence microscopes often use double tube eyepieces for easy observation.
