@carolmdieter that’s tricky - we need distance from the LEDs to get even illumination, so maximum height is a lot less than the distance from the carousel surface to the frame “ceiling” (in which the LEDs are mounted) - Also there’s the question of centrifugal force which means that higher objects need stronger support.
Mainly I’d say its about illumination. Between the fish and the frogs, with the height of the fish at 3.5cm at the perimeter and most of the frogs under 1.5cm - there’s already a noticeable difference in illumination. The fish are noticeably dimmer in the spaces not directly under the LEDs.
So I’d say 4cm is a maximum for objects near the edge.
Near the center though there’s more even light and less centrifugal force, so you could probably go as high as even 10cm at the inner edge, although this would make slotting the carousel on to the hub awkward, since you wouldn’t be able to see the top side of the hub.