Which objective lens should be placed above the hole in the stage when you first begin to focus the specimen?

or before you store the microscope? Assume the microscope you are using has four objective lenses.Which objective lens should be placed above the hole in the stage when you first begin to focus the specimen?
a low power objective. Usually it will be a 10x lens.

Assuming the lenses are all pretty much parfocal as they ought to be.

flyff