Microscope magnification and effective magnification
Due to the two magnifications of the objective lens and the eyepiece, the total magnification Γ of the microscope should be the product of the objective lens magnification β and the eyepiece magnification Γ1:
Γ=βΓ1
Obviously, the microscope can have much higher magnification than the magnifying glass, and the magnification of the microscope can be easily changed by exchanging objective lenses and eyepieces with different magnifications.
Magnification is also an important parameter of the microscope, but you cannot blindly believe that the higher the magnification, the better. The limit of microscope magnification is the effective magnification.
Resolution and magnification are two distinct but related concepts. There is a relational formula: 500NA<Γ<1000NA
When the numerical aperture of the selected objective lens is not large enough, that is, the resolution is not high enough, the microscope cannot distinguish the fine structure of the object. At this time, even if the magnification is increased excessively, only an image with a large outline but unclear details can be obtained. , called the ineffective magnification. On the other hand, if the resolution has met the requirements and the magnification is insufficient, the microscope has the ability to resolve, but the image is too small to be clearly seen by the human eye. Therefore, in order to give full play to the resolving power of the microscope, the numerical aperture should be reasonably matched with the total magnification of the microscope.
