The Leica system is excellent-I have seen it. My reservations regarding the piezo-electric stage remain and are amplified by the comments from Martin Hoppe. The "sample weight which can be put on the stage is 250 grams." In my own application I need to use a fixed stage carrying several kilograms of apparatus (primarily micromanipulators) which are used with an in vivo preparation. The point is that the Leica system is simply not suited for what I need. I am not criticizing Leica, rather, I am looking for a different solution to the rapid z-scanning problem. Still no comments on the new Olympus America "Fluoview" scope. Roger Adamson