interesting picture

[stevec]

Wait! What kind of camera? Digital? why would they be 50 or 60 Hz. Are they "plug in the wall" cameras?
Or am I missing (something else) here?

[TomG]

The fluorescent light above was acting like a strobe.

Tom

[doubleboost]

(03-29-2013, 07:32 PM)TomG Wrote: The fluorescent light above was acting like a strobe.

Tom

I think that was it Tom
Strobe effect
Our mains is 240 volt 50 Hz

[EdK]

Yup, it's because of the strobe effect. That's why you should never have just a fluorescent light above your table saw. Include an incandescent bulb also to help eliminate the strobe effect which can make the saw blade appear to be not turning. I know of someone who got their finger cut off as a result of the strobe effect.

Ed

[Rickabilly]

The 50Hz "ripple" can be seen on an incandescent bulb too, if you hook a high speed Cadmium Sulphate photo resistor up via a battery and measure the output on an oscilloscope but no where near as much as with a fluorescent tube or these days a compact fluorescent bulb (tricky little blighters look just like a proper bulb but strobe like a fluoro tube). Halogen spot lights whether high or low voltage, strobe less than even an old school bulb due to the thicker filament so use these on your work lights to get away from strobing issues.
Regards
Rick

[Hawkeye]

I built an optical tachometer years ago to measure engine speed on RC airplanes. I used standard light bulbs to calibrate it. Definite strobe effect.