If a laboratory professional switches from a 40x objective to a 10x objective and the specimen remains in focus, how are these microscopes described?

When a microscope is described as parfocal, it means that when the objective lenses are changed, the specimen will stay in focus or require only minor adjustments to remain in focus. In the scenario given, when switching from a 40x objective to a 10x objective and the specimen remains in focus, it indicates the parfocality of the microscope. This quality is important for laboratory professionals because it allows for efficient transitions between different magnifications without significant loss of focus, thus maintaining the continuity of observation and analysis.

The other terms do relate to the performance and features of microscopes, but they don’t directly pertain to the behavior observed in this situation. For example, parcentric refers to the ability of the microscope to keep the specimen centered in the field of view as objectives are changed, which is not the focus of this question. Compensated and parachromatic are terms generally related to corrections in optics, such as color correction, rather than the ability to maintain focus during objective changes. Therefore, the focus on the ability to switch magnifications while retaining clarity is what establishes the microscope as parfocal.