[SML] WiFi video camera

[Ford Sellers]

Friend to the list Dan Sheehan wrote:
could I guess maybe NTSC originated in 60-Hz  AC power land and PAL in 50-Hz mains land ?

does that make any difference anymore ?

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...Dan Sheehan
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Ford replies:
It can when you are working with LED lighting which dims via PWM.

Any of your new(ish) higher-end fixtures will be ok, but your low-end DJ grade LED lights may show a flicker on one, or the other (or both).
If, for instance you have a refresh rate of 650hz, you will see flicker on NTSC (60hz native), but not on PAL (50hz).
Whereas at 600hz, you will not see flicker on either (typically).

Early (relatively speaking) professional LED washilghts used a PWM rate that was a multiple of 50 and 60 to prevent this.
300hz was considered ok for cameras, but some with sensitive eyes saw the flicker (I know I did).  So most manufacturers went to 600hz.
Typically, Chauvet units from 2008-2012 were developed with a 600hz refresh rate.  This kept them stable on most cameras, and visually appealing.
More recently we have used 1200hz as the base level, and some have variable up to 24khz.  This allows them to be used on various professional grade cameras.

HTH,
-Ford