Synchronising cameras

[PaulFreeman]

I found this site, because I was looking for ways of triggering Canon cameras synchronously.

I experimented with pocketwizards firing two Canon cameras but found that there was a variation in delay between the two cameras. Of course I fixed both lenses on manual focus.

Looking at the remote capture notes I notice that variable delays of 20-30 msec are cited, with the possibility of shortening this if the camera AF mechanism is woken up.

This variation is too great for my application, viz 20 msec is 1/50 second and 30 msec about 1/30.

I wonder if anyone has any idea of how much shorter these delays are once the AF has woken up? I'm also wondering if, in anyones experience, these delays are consistent for a particular camera? ie: is there a wide variance between delays for a single camera?

I'm trying to shoot a moving subject in available light from multiple perspectives at the closest synchronisation possible. Its a challenging project. So far my best result was using film cameras triggered mechanically, but I'd really like to be able to use digital cameras because of the high iso performance.

[Chris Breeze]

There's bound to be some variation between cameras due to manufacturing tolerances but I think you'll also find that the lag isn't constant for a given camera and depends on how busy the camera's processor is when the shutter release is actually pressed. Using manual focus, manual exposure and half pressing the camera's shutter release before taking the picture should help to minimize this.
The Pocket Wizards may also be introducing some variation in the timing.

[rolland_elliott]

I read in the past about a company doing these bullet time matrix effects and they used cheap canon digital rebels and set them all to custom function 12 so the mirror was pre flipped up. This reduced variation enough so that it worked fine.

I have a new question though I want to use around 10 or 15 S5 point and shoot cameras to make 3D lenticular prints using black light strobe photography. Is it possible to have all cameras fire in sync with a strobe that is only hooked up to one of the S5's hot shoe?

I'm guessing a longer exposure in a black room with a flash pop might be required?

[Chris Breeze]

No it's not possible to fire multiple PowerShot cameras at the same time. When they are connected to a PC they can only be fired sequentially with a delay of approximately 1/6 sec delay between each camera.

With DSLR cameras you can wire the remote shutter releases together and fire them at the same time.

BTW I've been working with a Hollywood special effects company who are using 120 Canon EOS 30D cameras for "The Matrix" style special effects. There are some shots of the setup on the multi-camera pages: http://www.breezesys.com/MultiCamera/index.htm

[rolland_elliott]

that looks like a pretty major operation! You'll have to post the end commercial so we can google at the results.

Peace, Rolland

[Chris Breeze]

It was a major operation - production, lighting, makeup, wardrobe, multicam camera team etc. The ad ran on the web for most of last year but has been replaced now.

[rolland_elliott]

so is it theoretically possible to buy 10 or 20 digital slr cameras and have them synch to one black light strobe? I'm guessing the shutter speed would have to be kind of slow to allow for variences in camera lag, etc. what's the fastest shutter speed you know of that multiple cameras can be synched to one strobe at?

Peace, Rolland

[Chris Breeze]

For the November 2006 shoot we were using 25 Canon EOS 30D cameras per PC. However, the latest Canon libraries only support 16 cameras per PC.
No strobes were used for that shoot and so accurate synching wasn't an issue.

You can get very good synchronization of multiple Canon PowerShot G9 cameras with PSRemote Multi-Camera if you use AF lock to avoid variable AF delays. I haven't got suitable timing equipment to measure it accurately but I have done tests where 7 cameras fire within about 1/100 sec of each other.

[rolland_elliott]

Hmm, this is just a pet project but winter is slower for me so I am trying to make this happen. You wrote before "No it's not possible to fire multiple PowerShot cameras at the same time. When they are connected to a PC they can only be fired sequentially with a delay of approximately 1/6 sec delay between each camera."

but in your latest post you say the g9's can be fired 1/100th. Are there any other powershot cameras that one can do this with?

Im trying to figgure out if it would be more cost effective to get 10 dslr's or 10 point and shoot cameras.

[Chris Breeze]

A few months ago I had 5 Canon PowerShot G9 cameras available for testing a custom multi-camera solution for a client and was able to try firing all at the same time. To my surprise if AF lock, manual exposure and preset WB are used the cameras all took pictures within 0.01 sec of each other. This wasn't 100% repeatable and sometimes the variation was +/- 0.06 sec, but more often than not, the cameras were within 0.01 sec. I also added a PowerShot S5 IS and SX100 IS to make 7 cameras in total and got similar results.

The biggest problem is the delay before taking the pictures. It takes more than one second from pressing the release button in the software to the cameras actually taking the pictures.

BTW My timing tests were not particularly rigorous or scientific. I simply pointed the cameras at a digital stopwatch with a 1/100 sec display and took the pictures.

[rolland_elliott]

thanks that is good to know. sounds like dslr's may be best for my project though a bit expensive.