Which knob is used for fine adjustments on a microscope?

The fine adjustment knob is specifically designed to allow for precise focusing of the microscope. When viewing specimens under high magnification, the depth of field is very shallow, which means that even slight movements can cause the specimen to go out of focus. The fine adjustment knob enables you to make small, careful adjustments to the stage position, allowing for clear and sharp images of the specimen being observed.

In contrast to the coarse adjustment knob, which moves the stage up and down quickly to bring the specimen into general focus, the fine adjustment knob provides the necessary control needed for detailed work. This precision is essential for tasks such as identifying cellular structures or distinguishing between closely located details in the specimen.

The revolving nosepiece serves to switch between different objective lenses but does not contribute to focusing the image. The stage adjustment knob allows you to move the stage left or right and up or down but does not provide fine focus capability like the fine adjustment knob does.