On Friday, 29 September 2017 13:08:29 UTC+1, Dave Plowman (News) wrote:
In article ,
Ash Burton wrote:
On 29/09/2017 04:25, Bill Wright wrote:
Warning: LED torches and cap lamps can cause a strobing effect that
can make rapidly turning things like drill chucks and grinder wheels
seem to be turning slowly or not at all.

Bill

A useful tip, this was a well known issue in factories and workshops
with fluorescent lighting but I'd not heard it before with LED lights.

Decent modern florries run at a much higher frequency than mains and don't
give this effect.

They do.


And unlike LEDs, the phosphors used have a degree of
persistence, so tend to minimise switching flicker.

LEDs tubes are meant to get around this by using a similar coating but as yet I haven't tested this like I have with our labs florry tubes.

unless of course you can explain this

notice the can rate and the light on the monitors case and on the wall behind.

https://www.youtube.com/watch?v=sVNDlV7iaO4
iphone at 240FPS


https://www.youtube.com/watch?v=ws_r6jKRmZU
iphone at 60FPS.