# How to trigger 2 cameras at the exact same time?



## flowers (Feb 12, 2014)

I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
Thank you for your help


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## privatebydesign (Feb 12, 2014)

A set of three Yongnuo YN 603's will do it, so will the RF602's, they are older and not transceivers though. 

What YN radio trigger are you using for the flashes?

But if you want one set of flashes to light for both cameras exposures you have another issue, same time is not the same as exact same time. If you truly need exact same time then I suspect you'd need Pocket Wizard Multi Max's or a custom delay programmable home made solution.


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## flowers (Feb 12, 2014)

privatebydesign said:


> A set of three Yongnuo YN 603's will do it, so will the RF602's, they are older and not transceivers though.
> 
> What YN radio trigger are you using for the flashes?
> 
> But if you want one set of flashes to light for both cameras exposures you have another issue, same time is not the same as exact same time. If you truly need exact same time then I suspect you'd need Pocket Wizard Multi Max's or a custom delay programmable home made solution.



I'm using 603's to trigger the flashes. The ones I have a different cable that can be used with the flashes but not the cameras so I need to buy another couple of sets. I have one 568EX II and the rest are the mark III versions of 560 which have a built-in RF so they don't need to be attached to anything. If they work that's great, because the trigger I use to fire the flashes would give the flashes and the cameras the command to fire all at the same time. 
I thought the flashes would expose the scene for both cameras at the same time by firing only once if I use shutter speeds below 1/180. Am I wrong? If they fire at different times within 1-15ms from each other they cause a double exposure on both cameras: images unusable. That is another reason it must be at the same time. Visually important: both images look like the same scene (frozen moment) from different angles. Technically important: flashes expose scene for both cameras.
I wanted to buy 4 more 603's anyway. I will try them and if it doesn't work I will look into PocketWizard. Sound good?
edit: sync speed for flashes and Canon cameras for YN radio tranceivers is 1/180, according to my experience it always syncs at speeds below 1/180.


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## surapon (Feb 12, 2014)

flowers said:


> I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
> Thank you for your help



Dear Flower my friend.
Try this Cheapo one

http://www.amazon.com/AmazonBasics-Wireless-Remote-Control-Canon/dp/B00BCEJ0E0

It work with in 10 feet, and Camera close to each other.
Good luck.
Surapon


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## flowers (Feb 12, 2014)

surapon said:


> flowers said:
> 
> 
> > I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
> ...


Thank you my friend Surapon, I did not think of that. At line of sight, of course speed of light = the same to both cameras! Very clever 
It will work for some situations. Sometimes line of sight is not possible and walls are too far away to bounce, that's why I need RF. But you are right, I did not even think of IR triggers. But I wonder: if one camera has a RF transceiver in the hot shoe and one doesn't, will the camera without the RF fire more quickly? I will have to try it.


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## flowers (Feb 12, 2014)

I wish Yongnuo would make a double tranceiver that could have 2 cables attached to two cameras.


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## privatebydesign (Feb 12, 2014)

Are you trying to get the shutters synchronized so they both work with the same flash pulse?


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## surapon (Feb 12, 2014)

Dear Friend Flower
Try to read this Link.

http://breezesys.com/MultiCamera/release.htm

Good luck.
Surapon


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## flowers (Feb 12, 2014)

privatebydesign said:


> Are you trying to get the shutters synchronized so they both work with the same flash pulse?


That is what I want but I am not very technical. I can't build anything electronic. Is there a way to do it?


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## flowers (Feb 12, 2014)

surapon said:


> Dear Friend Flower
> Try to read this Link.
> 
> http://breezesys.com/MultiCamera/release.htm
> ...


Thank you for the link dear Surapon, but I am not very technical  I don't understand what I should do?
The link has sentences like... "You will need to write your own software but any competent programmer should be able to do this. " I am not a programmer, I cannot do anything like that, I don't understand at all. I'm sorry!
Maybe I am not smart enough for this, maybe it's impossible if you are not an engineer and a programmer? If that is true, please tell me and I will forget about trying it.


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## surapon (Feb 12, 2014)

Dear Friend Flower.
I have so many RF. wireless controls sytems ( Many Brands name) , I will try and Report to you with in 2 days.
Well, I am the Cheapo, Brainless, But Adapter, try to adapt until It's work.---Ha, Ha, Ha.
Good night.
Surapon


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## flowers (Feb 12, 2014)

surapon said:


> Dear Friend Flower.
> I have so many RF. wireless controls sytems ( Many Brands name) , I will try and Report to you with in 2 days.
> Well, I am the Cheapo, Brainless, But Adapter, try to adapt until It's work.---Ha, Ha, Ha.
> Good night.
> Surapon


Ha ha okay, thank you! I will try it myself when I get more YN triggers! I will get more maybe next week. Then I will try myself. If you try earlier please let me know! But please don't trouble yourself for me  I am also cheapo when I can, I don't buy cheap, bad quality lenses or cameras but I also try to find cheap ways to have accessories! Like softboxes, diffusers (tracing paper and build your own!) radio triggers (if Chinese models work as well of course I use Chinese! or other cheap brand) that kind of things. Cheap accessories = more money for lenses! Good night to you too


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## Kahuna (Feb 12, 2014)

surapon said:


> Dear Friend Flower.
> I have so many RF. wireless controls sytems ( Many Brands name) , I will try and Report to you with in 2 days.
> Well, I am the Cheapo, Brainless, But Adapter, try to adapt until It's work.---Ha, Ha, Ha.
> Good night.
> Surapon



and this is why I enjoy this site so much. Mr. Surapon you ROCK!!


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## surapon (Feb 12, 2014)

flowers said:


> I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
> Thank you for your help



Dear friend, Flower.
Yes, I test for all of my RF Cheapo wireless remote control sets, and High cost Phottix Odin too---Not work.
EXCEPT Phottix Cleon ( 4-5 years old) I use two set of Receiver and 1 Transmitter = WORK with in 30 Feet---From difference room too---do not need On site of Line/ Eyes---Yes, After Plug the receiver units on 5D MK II and 7D, we need to set 2 second timer at the camera = YES, AF WORK TOO.
4-5 years ago I brough Phottix Cleon = $ 30 US Dollars per set, Now They sell Phottix CLeon MK II for $ 36 US Dollars per set.

http://dealspl.us/product/phottix-cleon-ii-c8-hybrid-wired-wireless-remote-set-for-canon

Good Luck.
Surapon


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## surapon (Feb 12, 2014)

Kahuna said:


> surapon said:
> 
> 
> > Dear Friend Flower.
> ...



Thousand Thanks, Dear friend Kahuna.
You make my days.
Surapon


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## flowers (Feb 13, 2014)

surapon said:


> flowers said:
> 
> 
> > I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
> ...


Dear Mr. Surapon, if I understand correctly: all RF sets you have, Yongnuo too, did not work? But Phottix Cleon worked? If that is true I will get Phottix Cleon! I wonder if the new version would work too, or only the old one? Hm


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## J.R. (Feb 13, 2014)

privatebydesign said:


> Are you trying to get the shutters synchronized so they both work with the same flash pulse?



that got me thinking. I can trigger two cameras using the 600RTs but Canon mentions that there is no way to guarantee it and thus disables multiple flash shooting in this mode. 

Is there a way to do it?


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## flowers (Feb 13, 2014)

J.R. said:


> privatebydesign said:
> 
> 
> > Are you trying to get the shutters synchronized so they both work with the same flash pulse?
> ...


triggering the cameras only is not the problem. in my planned setup only 1 camera triggers all the flashes and only 1 radio trigger triggers both cameras. it should work but the question is: will the second camera have its curtains open during the firing of the flashes? When more triggers arrive in the mail I'll give it a try. According to Surapon it will only work with Photix Cleon. I'm using YN flashes and triggers so there are no limitations.


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## surapon (Feb 13, 2014)

flowers said:


> surapon said:
> 
> 
> > flowers said:
> ...




Dear Friends , Flowers.
Sorry, I do not have Youngnuo RF UNITS, But Youngnuo should do the same thing as all AF. Remote control unit do---If have the right Wire to hook to the cameras.
Sorry again, I Have Phottix Cleon I, Not MK II----I do not try MK II yet.
Have a great day.
Surapon


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## flowers (Feb 13, 2014)

surapon said:


> Dear friend, Flower.
> Yes, I test for all of my RF Cheapo wireless remote control sets, and High cost Phottix Odin too---Not work.
> EXCEPT Phottix Cleon ( 4-5 years old) I use two set of Receiver and 1 Transmitter = WORK with in 30 Feet---From difference room too---do not need On site of Line/ Eyes---Yes, After Plug the receiver units on 5D MK II and 7D, we need to set 2 second timer at the camera = YES, AF WORK TOO.
> 4-5 years ago I brough Phottix Cleon = $ 30 US Dollars per set, Now They sell Phottix CLeon MK II for $ 36 US Dollars per set.
> ...


Dear Mr. Surapon, if I understand correctly: all RF sets you have, Yongnuo too, did not work? But Phottix Cleon worked? If that is true I will get Phottix Cleon! I wonder if the new version would work too, or only the old one? Hm 
[/quote]


Dear Friends , Flowers.
Sorry, I do not have Youngnuo RF UNITS, But Youngnuo should do the same thing as all AF. Remote control unit do---If have the right Wire to hook to the cameras.
Sorry again, I Have Phottix Cleon I, Not MK II----I do not try MK II yet.
Have a great day.
Surapon
[/quote]

Oh, I understand! When I get more Yongnuo RF units and cables I will try it! I will post about it in the forum. If it works I will let you know!  Have a great day as well Mr Surapon.


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## Halfrack (Feb 14, 2014)

flowers said:


> I've never had to do this before so I'm relying on your help. How can I trigger a 5d2 and a 7d at the _exact_ same time? (MF prefocused of course) Ideally without anything mounted to the hotshoe of both cameras as I need at least one hot shoe equipped with a YN radio trigger to trigger all the flashes.
> Thank you for your help



What is the scene you're trying to capture? Look into bullet time rigs and downsize. Or look at using constant lights instead of strobes, as being off 1/180th of a second is the difference between the shot or black frame right?


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## noisejammer (Feb 15, 2014)

A lot depends on what you're trying to photograph, how much background light it present and how bright your strobe is. 

If you can set the shot up so the cameras are in the dark, the obvious way is to open both apertures and then fire the strobe. If you do this, your images can easily be synchronised to less than a millisecond. Don't control the strobe with either camera - you can use the strobe's light measurement to get the exposure about right

If this isn't practical then you need to define how closely you want the exposure to be fired because the 5D2 and 7D have different delays when you trip the shutter. It certainly helps if you can set the cameras to the same exposure (trade off ISO against f-stop) and run everything in manual mode. You can then use a wired connection and put them in parallel (I think this will work if they are wired together but - some electrical buffering would probably be better.)

Another random thought - if you have an ultra-fast strobe (say a Q-switched laser), don't forget that light travels at a finite speed - this can make a difference. You need to get the distance to the subject the same for all the cameras.


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## flowers (Feb 15, 2014)

noisejammer said:


> A lot depends on what you're trying to photograph, how much background light it present and how bright your strobe is.
> 
> If you can set the shot up so the cameras are in the dark, the obvious way is to open both apertures and then fire the strobe. If you do this, your images can easily be synchronised to less than a millisecond. Don't control the strobe with either camera - you can use the strobe's light measurement to get the exposure about right
> 
> ...


Oh thank you, you make so much sense! I don't have ultrafast strobes, the fastest my speedlights do is 1/20000s. It's fast enough for almost anything but not for freezing bullets of course. I am not good with electronics, I wouldn't know how to wire the parallel without them exploding! There are some millisecond timers on the market. Do you know if it's somehow possible to sync two wired timers? If I set a different delay to each timer (different by the amount of ms that the shutter delay of the two cameras differ) and could sync the time release triggers then it might work. Ambient light won't be a problem, I can get it down to absolute zero (minus light leak from the cameras and the strobes after I put black gaffer tape on all the lights and lcds) if I need to. The problem is that the strobe duration is so much shorter than the shutter speed that the shutter has to be open when the strobe fires, not the other way around. The shutter durations can overlap as much as they want, but can both be open at the same time? My master speedlight has HSS and can sync all the way up to 1/8000 when on the camera (I haven't tried it with a hotshoe extension cable but I doubt it would work). It can only sync up to 1/180 when off the camera. Wait a second...
*I just had an idea!* Tell me if this would work: I set all the strobes to fire at the command of one camera, the one with *shorter* shutter lag. I set the same shutter speed for both cameras. I set all strobes to rear curtain sync. When the 2nd curtain of the faster camera is about to come down, the flash fires. 

Shutter lags:
5d2: 206ms
7d: 131ms
Shutter speed: 1/4s (250ms)
5d2 shutter open: from 206ms to 456ms
7d shutter open: from 131ms to 381ms

7d 2nd curtain coming down: at about 375ms, strobes fire
at 375ms, 5d2 shutter still open: check!

I think that would work!


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