Which optical system is essential for achieving maximum light-gathering capability in a compound light microscope?

The condenser lens is essential for achieving maximum light-gathering capability in a compound light microscope because it focuses light from the microscope’s light source onto the specimen being observed. This lens is crucial for illuminating the sample evenly and efficiently, which in turn enhances the resolution and contrast of the image produced by the microscope.

The condenser lens helps to concentrate the light rays into a cone that illuminates the specimen, allowing for greater detail to be visible than would be possible with less effective illumination. This control over the light allows for improved visibility of fine details, which is critical in microscopic analysis.

Other components like the objective lens and ocular lens play vital roles in image formation and viewing but do not directly influence the amount of light that can be gathered from the specimen itself. The aperture can influence the light that passes through when observing, but it is the condenser that primarily focuses and optimizes this light-gathering process.