Most microscopes are parfocal. This means that the distance from the nose piece opening to the focal plane of each lens has been
standardized. What does this mean to you with regard to how you use the microscope?A. When the specimen is in focus, the slide will always be the same distance away from the end of the lens no matter which lens is being used.B. Once the specimen is in focus under a low power lens, the microscope can be switched to a higher power lens without moving the stage and the image will be in or nearly in focus no matter what lens is used.C. All lenses will need to be used the same way, either through air or through oil.D. That the interpupillary distance and ocular focus ring will need to be adjusted for every lens being used.
B. Once the specimen is in focus under a low power lens, the microscope can be switched to a higher power lens without moving the stage and the image will be in or nearly in focus no matter what lens is used.
