The condenser is a vital component of the microscope for several reasons:

Image Quality:

It directly influences image contrast, resolution, and overall quality.  

A properly adjusted condenser maximizes the performance of the objective lenses.  

Specimen Visualization:

It enables the visualization of different types of specimens, including stained, unstained, and living cells.

Different condenser types are required for different microscopy techniques (e.g., brightfield, phase contrast, darkfield).  

In summary, the condenser is not merely an accessory but a critical component that significantly impacts the quality and effectiveness of microscopic observations. Proper understanding and utilization of the condenser are essential for achieving high-quality images and maximizing the potential of the microscope. There is a guide about How to Adjust the Condenser for the Microscope you might also want to get.