These video files are freely distributed under license Creative Commons BY-NC-ND 3.0
In viewing frame by frame, it is possible to change the focus as if you have your eye on the microscope. To perform an accurate count, you will need a graphics program managing layers and stack into it some snapshots of the video or, more simply, use transparent plastic sheets placed on the screen.
1. - cf. Donati D. & Dumont G. (2013), Sempervivum soculense, in Acta Succulenta 1(2): 116-146.