Nikon Flash with Canon Rebel XT Camera

[emmanuel_rondeau]

<p>Hello everyone,<br /><br />I'm working on a camera trap setup. I'm using 350D (Rebel XT) camera bodies, Nikon SB-28 flashes and PC cable to makes them work together, as well as a infrared beam system to trigger the camera when a subject is moving.<br>

(I'm using SB-28s because they hold the charge way better comparing to Canon flashes. I leave the setup out in the wild for several weeks/months, that's why I need to use the stand by mode on the flash.)<br /><br />My problem is the following : The flashes works only from the second shot. The first shot makes the flashes to wake up, and then the second shot is properly exposed with the flashes.<br /><br />It is a major problem with me since the first shot can be a 30 sec exposure, and so the 2nd shot can simply never happen. I need the fist shot to trigger the flashes.<br /><br />If you have any clue, I would strongly appreciate it.<br>

Thanks ! </p>

[Charles_Webster]

<p>Using the standby mode is exactly what's causing your problem. The first shutter click takes the flash out of standby, and the second fires the strobe.</p>

<p>You can't have both, standby and instant response.</p>

<p><Chas></p>

[bob_sunley]

<p>Why are you getting a 30 sec exposure? maybe modify your trigger to put out two pulses a second apart or whatever is needed to wake up your flashes and set your shutter speed to a fixed value. That way your flash will wake up first.</p>

[Charles_Webster]

<p>Why not use a dedicated game camera such as this</p>

<p>http://tinyurl.com/7gq4xwj</p>

<p><Chas></p>

[emmanuel_rondeau]

<p>Thanks a lot for your answers.<br>

Charles, that's what I'm afraid of, but I've seen people making this setup to work, so there must be a solution somewhere. As for the other camera you suggested, it is not an option since the result are artistically miles from the quality of a DSLR camera.<br>

Bob, I'm (sometime) getting a 30 second exposure because the camera can be triggered at night, so the flash is lighting the foreground (subject) and the 30 sec exposure is lighting the background (like the stars). On your second tought, that's actually what I did, my trigger is putting out 5 or 6 pulses so that the flash is awaken and then the shots are taken, of course this only works with a fast shutter speed.<br>

Just to share what I'm thinking about, I think the ONLY solution would be to actually hack the camera firmware (with this http://chdk.wikia.com/wiki/CHDK) to make the camera to take a "fake and fast" first image before actually taking the real images. Makes sense ?</p>

[Charles_Webster]

<p>I don't see any DSLRs on the supported camera list at that site. Are you sure your 350D is supported?</p>

<p>And I don't see any options to create the kind of triggering activity you seek. Where did you see that capability?</p>

<p><Chas></p>

[phule]

<p>Charles, the DSLR work is under the "For Developers" section with a warning that at least one person cratered their 350D. There's a long (26 page) thread detailing the work since it began. Recent replies seem to indicate that it's working fine but it should be emphasized that this is very much an "At Your Own Risk" move. </p>

<p><a href="http://chdk.wikia.com/wiki/350D">http://chdk.wikia.com/wiki/350D</a></p>

[rawrainforest]

<p>Hi Emmanuel,<br>

I feel for you. Planning cam-trap work for editorial work in upper Amazon basin. When you are looking for SB-28’s do not buy the DX model. It is cheaper but does not have a good standby mode and will only last about 24 hours. The SB-28 charges up the capacitors that provide the high voltage for the flash before going back into standby and then monitors the voltage when in standby. This gives it instant wakeup. Good call on setting the triggering pulse. The recharge time between shots is dependent on the intensity of the flash as you know, but do consider researching animal's seasonal and daily behavior, so you can devote batteries to best times. You may have better results at dusk/dawn and just set an exposure for that.</p>

[emmanuel_rondeau]

<p>Charles, the option I'm seeking has not been developed but I was thinking about develop it myself or a friend of mine.<br>

Hi Bruce, thanks for your very interesting feedbacks. I actually own "normal" SB-28's, not DX, and even with those I'm getting the behavior I described. What setup are you using ? have you faced the same problem I'm currently facing ?<br>

One thing though, I've been experimenting with a 1D III and its 10fps, and as soon as the second frame (so 100 milliseconds after the first shot), the flash works, so that means it is actually not time that the SB needs to wake up, it is just signal. It looks like they need a first signal to say "WAKE UP" and then a second signal to say "TAKE THE PICTURE". So basically I'm looking for a way to send 2 signals in the same time...</p>

[emmanuel_rondeau]

<p>UPDATE TO THIS OLD POST!<br>

It is has been a while, and I have been reminded of this old post by someone on the web. Anyway, I found the solutions to all those problems and wrote a complete ebook to explain how to build efficient DSLR Camera Trap, using CANON Rebel cameras and Nikon SB28 flashes.<br>

If you are interested, have a look :<a href="http://www.emmanuelrondeau.com/publications/dslr-camera-trap/">http://www.emmanuelrondeau.com/publications/dslr-camera-trap/</a></p>