# Lighting Reikan Focal Targets



## Ozarker (Jul 25, 2015)

I just downloaded the software and printed the targets. I have a bunch of LED lights made for photography, but the instructions say not to use LED "mains" lighting. I have no idea what "mains" is. I've never AFMA my lenses, so I am very new at this. What is "mains" when it comes to LED lighting?


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## kaihp (Jul 25, 2015)

What they're concerned about is lights that flicker, so you don't get a uniform lighting from shot to shot.
Sometimes you can see the flickering by taking a video with a framerate that is't the multiple of your mains rate.
Or, you could just try to take 10 pictures in a row with, say 1/200sec shutter and see if they are consistently lighted.


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## retroreflection (Jul 25, 2015)

"Mains" is the generally British term for alternating current electrical power from the outlet.
If the LED power supply does nothing fancy, the light will vary at 50 or 60 Hz, depending on your country (or latitude in Japan). It is possible to build a power supply that greatly diminishes the effect, or run straight off of batteries.


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## Ozarker (Jul 25, 2015)

kaihp said:


> What they're concerned about is lights that flicker, so you don't get a uniform lighting from shot to shot.
> Sometimes you can see the flickering by taking a video with a framerate that is't the multiple of your mains rate.
> Or, you could just try to take 10 pictures in a row with, say 1/200sec shutter and see if they are consistently lighted.





> "Mains" is the generally British term for alternating current electrical power from the outlet.
> If the LED power supply does nothing fancy, the light will vary at 50 or 60 Hz, depending on your country (or latitude in Japan). It is possible to build a power supply that greatly diminishes the effect, or run straight off of batteries.



Thanks so much for your responses. My LED lights can use batteries, so that is what I'll do. Again, thank you!


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