oil sight glass almost impossible to gauge

[CRH]

Incidentally just been out to recheck and decided to look at glass while engine was running. The oil drops to only just below the top dot while running and the reason I was not seeing a level when getting down after engine stopped is because it literally refills in seconds.  So I would now ask (if I hadn't been made to feel silly for asking questions with obvious answers) If anyone had looked at glass while engine was running and taken mental note where their level is in relation to dots.

....Mmmmm?...now that is wierd midden?....mine dissapears completely when i run mine!!..and only show the correct level again when i switch off?... :rolleyes ....that is on center stand btw?