Multiple strobes - sync cords

Hi Gents,

I made a posting earlier in the week, regarding multiple strobes and pocketwizards required for triggering them all remotely - I had some great advice from you guys, and will be purchasing some of them in the next couple of months.

In the meanwhile, I'm about to purchase 2 more 500W strobes to add to my collection, as I'm shooting some rather large surface areas next week.

As I've mentioned before, I currently have a sync cord that goes from the camera to one of the strobes, with the other strobe triggering via radio / whatever system it uses, once the main strobe has gone off.

I'm aware that you can hook up multiple strobes using sync cords, which are all triggered by the one single device - what does this require, some kind of sync cord "junction" or something similar? If so, what is this called, and does anyone know of any online retailers I can order such a device from? (preferably UK ones)

Many thanks.

Alvaro

Not knowing how many flashes you are going to try and trip I would first put one of these on top of the camera.

http://www.bhphotovide​o.com …EG&addedTroughT​ype=search

then all you need is some of these

http://www.kentonuk.co​m …ors_splitters/b​1-hc3.html

and

http://www.kentonuk.co​m …o_jack_leads_/b​1-bc6.html

Bob

It is not a smart idea to connect more than one strobe to a camera's PC connection. This is especially true if the strobes are not identical, because you would have different trigger circuits with different voltages on them.

However, even if the strobes are identical there can be problems. The reason is simple. Two identical strobes, when connected in parallel to the camera, will cause twice the current to flow through the switching circuits in the camera. Three strobes would cause three times the current of one to flow through the switching circuits.

Since Canon does not advertise the voltage limits very well and does not advertise the current limits at all, it is not wise to exceed the current from a single flash unit going through the camera's switching circuits. It doesn't make any difference that people make connectors that allow the possiblity of connecting several flash units to one camera. The manufacturers of the connectors are not going to repair your camera if its switching circuits get damaged.

The two best solutions for multiple flash triggering are: 1) Use the built-in optical slaves for all but one flash unit, or 2) Use radio slaves for the whole package.

I take it the built-in optical slaves you talk about, are what currently makes one light trigger the other without any wires?

I currently have two Bowens 500W Gemini Esprit stropes, and have been trying to figure out how one strobe trigers the other - I assumed it was some kind of built-in wireless or radio system, but I'm assuming what you say here is that they detect each other by "seeing" each other flash?

I had loads of problems the other day getting them to trigger properly, with one light refusing point blank at times to trigger - is this because they need to be able to "see" each other when triggering?

Alvy wrote in post #2891106
I take it the built-in optical slaves you talk about, are what currently makes one light trigger the other without any wires?

I currently have two Bowens 500W Gemini Esprit stropes, and have been trying to figure out how one strobe trigers the other - I assumed it was some kind of built-in wireless or radio system, but I'm assuming what you say here is that they detect each other by "seeing" each other flash?

I had loads of problems the other day getting them to trigger properly, with one light refusing point blank at times to trigger - is this because they need to be able to "see" each other when triggering?

Most monolights have built-in light receptors which detect another flash going off and will trigger itself based on that. Yes, each slaved flash unit has to "see" the master. In a studio environment, this is seldom a problem because of the light being reflected around the studio. Outdoors, however, I have sometimes needed to use external slaves (I use Wein Peanut slaves on the end of the PC cords) to allow the slaved flash units to trigger optically off the master.

What happens with your strobe is that they are right now being triggered by an optical slave...

What that is is a little eye that when it see's something really bright it set's off the flash.

it works the same way as street lights, it get's dark out the light come on.


What Skip said is correct.

You have 1 fash hooked to the camera right now, and what happens when you push the shutter button is the camera turns on a light switch just light you do when you want the lights on in your kitchen.

What skip is saying is right now your kitchen light switch is controling just 1 light and if you put your whole house full of lights on that one switch then the switch will fail, and it will.

What I'm saying is to protect the switch which is why I said to use the safe sync, or some other device that protects your light switch. then if you hook up too many lights the cheap "fuse" will blow not your camera (burn the house down) from the overload.


that being said I can say I have tripped more than one strobe off my camera's jack.

Bob

Sometimes the built in slave's light sensor inside the strobe goes bad and regardless of how close the other flash is to it it refuses to fire. In that case just plug in a auxilliary slave into where you plug the pc cord into and it should fire it.

If your strobe's slave faces the backside of the light and won't fire at times because of a weak or non-existant fill light you can take aluminum foil tape (the real shiney type) and make a crescent shaped reflector and tape it around the slave and it will bounce light into the slave.

Benji

Well, if it's a bad idea to connect strobes in parallel may be we can connect them in a sequence?
I am thinking if I can connect two strobes to one PW receiver ...

Kostyanych wrote in post #2912518
Well, if it's a bad idea to connect strobes in parallel may be we can connect them in a sequence?
I am thinking if I can connect two strobes to one PW receiver ...

The pocket wizard is just a switch. The only way to get one switch to fire two distinct flash units is with a parallel connection.

I am not saying that this is not ok (or ok), only that the nature of the connection must fundamentally be wiring that is "parallel".

Enjoy! Lon

Thanks for the info.
But what is actually firing the flash? Current?

I think series connection might work, cause the circuit is completed either way when you trip the switch - but can you imagine the hassle of series connection with a 2-3 flashes? camera - flash1 - flash 2 - flash 3 - camera?

After you trip over and break something you'll either buy a second slave or a pocket wizard.

Kostyanych wrote in post #2912873
Thanks for the info.
But what is actually firing the flash? Current?

Voltage and current, but all this is coming from the flash unit itself. The camera, radio slave, optical slave, etc only provides a simple switch to complete the circuit.

The simplicity and elegance of this design is noteworthy.

Enjoy! Lon

DocFrankenstein wrote in post #2912893
I think series connection might work, cause the circuit is completed either way when you trip the switch - but can you imagine the hassle of series connection with a 2-3 flashes? camera - flash1 - flash 2 - flash 3 - camera?

After you trip over and break something you'll either buy a second slave or a pocket wizard.

Ok, then I challenge you to draw a series circuit where one switch (as with one Pocket Wizard) turns on more than one flash unit, where the flash units has two contacts that must be bridged before the said switch will fire the flash (this is the way these flash units fire, two contacts are bridged).

Flash units are not strings of christmas tree light bulbs (like resistors).

Your fears of a catastrophe due to this series connection with a Pocket Wizard will never occur, as "the nature of the connection must fundamentally be wiring that is parallel."

Hey, I just quoted myself.

Buy the way, how are those new optical slaves and cords doing?

Enjoy! Lon

londuck wrote in post #2912977
Ok, then I challenge you to draw a series circuit where one switch (as with one Pocket Wizard) turns on more than one flash unit, where the flash units has two contacts that must be bridged before the said switch will fire the flash (this is the way these flash units fire, two contacts are bridged).

Flash units are not strings of christmas tree light bulbs (like resistors).

It depends on the flash design. All you have to do is trip the circuit.

If you have them in series and the first flash the fires doesn't break the circuit, then it will act as a conductor and will trigger the second flash. (EDIT: won't prevent triggering of the second flash actually)

If the first flash that fires DOES break the circuit, then you have problems.

but to say that you CAN'T fire two flashes in series is not entirely accurate without knowing the flash design/response.

They're great. I am still getting a stupid grin on my face thinking of what a good deal it was. lol

DocFrankenstein wrote in post #2913610
It depends on the flash design. All you have to do is trip the circuit.

If you have them in series and the first flash the fires doesn't break the circuit, then it will act as a conductor and will trigger the second flash. (EDIT: won't prevent triggering of the second flash actually)

If the first flash that fires DOES break the circuit, then you have problems.

but to say that you CAN'T fire two flashes in series is not entirely accurate without knowing the flash design/response.

All studio flash units fire exactly the same way, the two sync terminals are just shorted out (the two terminals are just bridged). You need no further education on the other aspects of the flash, brand of flash, etc. Any I can assure you that knowing absolutely nothing else about these flash units does allow me to "say that you CAN'T fire two flashes in series" (using only one pocket wizard).

You cannot short two contacts, on two different flash units, using only one switch (the pocket wizard) without this being a parallel circuit.

You talk a good circuit in ambiguous terms, but translate that talk into a diagram that will actually work.

You will discover that any circuit you draw, that will actually work, will be a parallel circuit, not a series one.

This is not a complicated circuit, it consists of the germane triggering aspects of two flash units, each just a positive and a negative terminal. And one switch (the pocket wizard).

So you have:

flash unit 1 with "+" and "-" terminals
flash unit 2 with "+" and "-" terminals
and a switch (the pocket wizard)

There are the only meaningful components in this parallel/series puzzle.

Enjoy! Lon