What is working distance in microscope?

Working distance in a microscope refers to the distance between the objective lens and the specimen being observed. This distance is important as it affects the amount of space available for various applications, such as manipulating the specimen, performing measurements, or introducing additional tools or equipment into the microscope. The working distance is typically measured from the tip of the objective lens to the closest surface of the specimen.

Working distance is determined by the design and specifications of the microscope objective. The higher the magnification of the objective lens, the shorter the working distance tends to be. This is because higher magnification requires the objective lens to be closer to the specimen for optimal imaging. On the other hand, lower magnification objectives usually have greater working distances, allowing more space for manipulations or use of auxiliary tools.

Working distance is an important consideration when choosing a microscope objective for a specific application. For example, in industrial or biological applications where delicate or bulky manipulations might be necessary, it is important to select an objective with a sufficient working distance to accommodate these tasks. Similarly, in microscopy techniques that require the use of additional equipment, such as fluorescence microscopy with specialized light sources or filters, a larger working distance may be required to accommodate the accessories.

Working distance can also influence the depth of focus in a microscope, which is the range of distance along the optical axis in which the specimen is in focus. Generally, objectives with longer working distances tend to have smaller depth of focus, while those with shorter working distances have larger depth of focus.

In summary, the working distance in a microscope is the distance between the objective lens and the specimen being observed. It is an important consideration when selecting a microscope objective for a specific application and affects the space available for manipulations, measurements, or introducing additional tools or equipment.