RobsonF wrote:
Shutter speed 1/60 of a second to account for any cycling in the compact fluorescent lights in my house.
Not trying to hijack your thread but just curious if an electrical engineer out there can enlighten us. I get that in north America we have 60 HZ, alternating current electricity, which as I understand it means that 60 times a second the flow of current reverses. As that happens the filaments in lights are energized from an \"off\" state, ramp up to full power and therefor full resistance and light output (volume and color), and then ramp down to the \"off\" state again. So if you visualize a continuous sine wave with 1/60th of a second between peaks or valleys, then overlay a 1/60th of a second exposure, it can fall anywhere along the cycle, but should, in theory encompass a full cycle. Therefor it would be identical to any other 1/60th slice of the cycle.
Is this assumption correct?
Now my real question here is - how accurate is the 60 Hz cycle, and how accurate is the 1/60th second shutter actuation?
The reason I ask is that if the 60 Hz is +/- 1 Hz and the shutter is say +/- 2%, you could have a 1/59th second exposure of a 1/61 cycle, which is then not necessarily equal to another 1/60th shot due to where it falls in the cycle.
All that to say to get a real certain full cycle would you want to be at say 1/50th or so? Or can you we count on a full cycle at 1/60th?
I hate it that I want to know this stuff. Sorry.
Jan 14, 2012 at 12:11 AM
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