effectively frozen typically at least three exposures must be taken for each placement of the specimen the rotation of the filter wheel should place the next sequential filter in the optical path at a time interval corresponding to the imaging device 39 s inter exposure cycle time a set of three exposures corresponding to three different wavelengths should be captured for each z axis depth of the specimen as an example images at nine focal planes may be required to completely characterize the specimen at a single x y position thus a total of 27 exposures would be required for each microscope field of view the z axis actuator should provide displacement satisfying all of these timing requirements the specimen must be scanned in the x y plane to fully image the specimen the scanning speed in the x y plane must be therefore permit the capture of 27 images for each microscope field of view image processing may be employed to correct registration between images necessitated by the various motion in an embodiment a side view of an automated microscope is provided as fig1 the stage 100 transfers the specimen slides from the cassette loaded in cassette handler 110 to microscopes optical axis 120 interchangeable filter carousel 130 as shown in fig2 is located on the microscope so that individual interchangeable filters 210 may be positioned on optical axis 120 filter carousel 130 is rotated by synchronized motor 135 electronic imaging device 140 may be a multi pixel planar array of light sensitive charge coupled device ccd or complementary metal oxide semiconductor cmos elements or any other technology suitable for converting an optical image into electrical signals low intensity detection can be.