Still Hz to think?

After my less than acceptable offering of almost a month ago 
(Tempus doesn't HALF Fidget, is it really that long?) I thought I'd try Plan B.
Took an "auto" - looked at it - 1/100 @ 1.8 = Close.
"Go on, try 1/50 or 1/60." 
So I did.
This is where the Hz start.   
;¬)   
I had, almost, forgotten our AC is ≈ 50Hz - in consequence, at 1/50 I was capturing approx. half a sine-wave at a time. But it doesn't really lend itself to 1 shot per day - for 3 days? 
Another aspect of the thinking Hz - Until I saw it through the viewfinder the flicker was imperceptible.

Neon -- the reason the, otherwise yellow, sodium vapour lamps started red & went to orange.