A mechanism for removably holding an objective lens in a microscope or scanner in a predetermined position the mechanism comprising: a kinematic base and an objective lens, the kinematic base defining an aperture therethrough, the kinematic base having defined on a first surface thereof facing the objective lens at least one of (a) a plurality of indentations and (b) a plurality of protrusions; and the objective lens having a second surface associated therewith facing said first surface of said kinematic base said second surface having at least one of (a) a plurality of protrusions which are alignable with the indentations (1040 a) on the first surface of the kinematic base and (b) a plurality of indentations which are alignable with the protrusions on the first surface of the kinematic base, wherein at least one of the first surface of the kinematic base and the second surface associated with the objective lens is made of a ferromagnetic material, the mechanism further comprising at least one of (a) a plurality of magnets which are installed within the second surface associated with the objective lens, when the first surface of the kinematic base is made of a ferromagnetic material, and (b) a plurality of magnets which are installed within the first surface of the kinematic base when the second surface associated with the objective lens is made of a ferromagnetic material, such that when said plurality of protrusions are aligned with said plurality of indentations and brought into proximity therewith, the optical axis of the objective lens is aligned with the aperture in the kinematic base and the plurality of magnets are sufficiently close to the ferromagnetic material to hold the objective lens in said predetermined position relative to said kinematic base. a kinematic base and an objective lens, the kinematic base defining an aperture therethrough, the kinematic base having defined on a first surface thereof facing the objective lens at least one of (a) a plurality of indentations and (b) a plurality of protrusions; and the objective lens having a second surface associated therewith facing said first surface of said kinematic base said second surface having at least one of (a) a plurality of protrusions which are alignable with the indentations (1040 a) on the first surface of the kinematic base and (b) a plurality of indentations which are alignable with the protrusions on the first surface of the kinematic base, wherein at least one of the first surface of the kinematic base and the second surface associated with the objective lens is made of a ferromagnetic material, the mechanism further comprising at least one of (a) a plurality of magnets which are installed within the second surface associated with the objective lens, when the first surface of the kinematic base is made of a ferromagnetic material, and (b) a plurality of magnets which are installed within the first surface of the kinematic base when the second surface associated with the objective lens is made of a ferromagnetic material, such that when said plurality of protrusions are aligned with said plurality of indentations and brought into proximity therewith, the optical axis of the objective lens is aligned with the aperture in the kinematic base and the plurality of magnets are sufficiently close to the ferromagnetic material to hold the objective lens in said predetermined position relative to said kinematic base.