Which magnification shows the feature of onion cells the best and why?

The best magnification to observe the features of onion cells is typically around 400x. At this magnification, individual cell structures such as the cell wall, nucleus, and cytoplasm become clearly visible without excessive distortion. Higher magnifications may provide more detail but can also reduce the depth of field, making it harder to view the entire cell structure in focus. Therefore, 400x strikes a good balance between detail and clarity.