# Camera rigging help needed
**URL:** https://boards.straightdope.com/t/camera-rigging-help-needed/347513
**Category:** Factual Questions
**Created:** [March 8, 2006, 6:54am UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513 "2006-03-08T06:54:02Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Joey\_P](https://boards.straightdope.com/u/Joey_P)
#### Post date: [March 8, 2006, 6:54am UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513/1 "2006-03-08T06:54:02Z")
To make a long story short I have a Nikon D70 and I need it to trigger a 120v power source. My idea is, hook a flash cable up to the shoe, wire the flash cabe to a relay and the other side of the relay to the power source. So here’s where I need help. First, does anyone know how many volts the shoe puts out. I’m thinking it would be a good idea to put a fuse in between the camera and the relay just in case the relay has a problem and sends 120v backwards, I’d hate to fry the camera. Second, the big question, what relay do I buy? I assume I look for one that’s rated to handle 120v on one side and whatever the camera voltage is on the other. Also, is there somesort something I can put on this attachment that will allow it to stay on longer. Not alot longer, like instead of instant (well however long the camera voltage stays up) about 1/100, 1/50…1/2 second. That would be really helpful, but I’m not sure what I’d be looking for, other then electronics, but I’m not looking to spend a ton of money. Any ideas? Am I making any sense?
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### Author:  [@GaryM](https://boards.straightdope.com/u/GaryM)
#### Post date: [March 8, 2006, 1:38pm UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513/2 "2006-03-08T13:38:39Z")
The camera “shoe” doesn’t output any voltage at all. It’s simply a switch that makes contact at the correct time to trigger the flash. The flash unit generates the voltage.
So to trigger your 120V source, you might not need a relay at all. How much current are we looking at here? Many digital cameras are rated to handle voltages up to 500V, but at a low amperage of course. A circuit consisting of a battery in series with the relay’s coil would work, as long as the relay didn’t require too much current to pull in.
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### Author:  [@Finagle](https://boards.straightdope.com/u/Finagle)
#### Post date: [March 8, 2006, 1:46pm UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513/3 "2006-03-08T13:46:43Z")
Most modern flashes trigger on very low voltages. Like 6 volts. Old flashes used to use very high trigger voltages on the order of 200-400 volts, but some digital cameras can’t take the voltage and can be damaged.
I’m a little confused as to what you want to control with the camera, but a relay may not be fast enough if you want whatever it is to appear in the picture. You may also have to worry about pre-flash triggering, depending on the camera.
A fuse is not going to help – it’s too high current. If that kind of current goes through your triggering circuit, kiss it goodbye. You’re going to want a rock-solid design that isolates your camera from the circuit being triggered. A relay _should_ do that, though.
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### Author:  [@spingears](https://boards.straightdope.com/u/spingears)
#### Post date: [March 8, 2006, 2:20pm UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513/4 "2006-03-08T14:20:01Z")
> [@Joey P](#):
>
> To make a long story short I have a Nikon D70 and I need it to trigger a 120v power source.
OoooKaaaaay.
Now just what do you want to accomplish?
Presumably to take a photograph. Right?
What are you going to trigger with the high voltage?
Perhaps you will need fast response solid state components.
Is the on time critical or can it be on a little longer that to on time of the camera shutter?
More information will yield more helpful answers.
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### Author:  [@Joey\_P](https://boards.straightdope.com/u/Joey_P)
#### Post date: [March 8, 2006, 2:42pm UTC](https://boards.straightdope.com/t/camera-rigging-help-needed/347513/5 "2006-03-08T14:42:58Z")
Okay, [here](http://www.dslreports.com/showpic/dimaging?lid=104192&folder=0) is what I’m doing (that’s my picture by the way). It’s a 9000v transformer I’m using to create an arc and then taking a picture of the arc. The problem is, if I leave the transformer on for more then a very very short time (about as fast as you can flick a switch on and off) there’s a sort of plasma cloud that get’s in the way and ruins the shot. Right now, I set the camera for 1 sec and while the shutter is open I flick the switch on and off just about as fast as I can. What I want to do is get the camera to control this. Now, for the protection of the camera I’ve decided against wiring anything directly to it, but I do have a wireless slave adapter. It uses the onboard flash to trigger another flash. I’m thinking of hooking the wireless adapter up to a relay with a battery in series with it, then the other side of the relay up to a 120v power source which will switch on and off the transformer. The shutter can be set to stay open for as long as I need it to, so if the whole setup takes a little bit longer to get going it’s okay. What I’m really looking for is the duration of the spark to be very short and I’m _hoping_ this will work. I’m mostly worried it will be to short and the transformer won’t have a chance to make the spark. So does this idea seem like it should work, or should I keep doing it by hand. (Which by the way yeilds more interesting pictures as I can’t control the timing all that well, but it might be nice to have control over the timing as well.)