How to use 580EXII and Vivitar 285HV and Sunpak DSU-01

<p>Hello all. I received a Sunpak DSU-01 for Christmas (it must have been on my "wish list") and I am having difficulty setting up my 580EXII and Vivitar 285HV with this unit. Is it even possible? My goal is to use BOTH the 580 and 285 OFF camera...can I do that? Do I have to use the 580 ON camera with the Sunpak and 285 OFF camera? Is my goal possible with these 3 units?<br>

The most simplified answer/set-up explanation is going to be GREATLY appreciated! Thanks, Pete.</p>

<p>Never used the Sunpak slave before, but I have used other slave units. You have to attach the Sunpak slave to the 285HV then the light from the Canon Flash should set-off the Vivitar attached to the Sunpak Slave. </p>

<p>You left out one critical piece of information, what camera you are using. IF, the camera is a 7D then yes you can have both the 580 and 285 off camera. As already mentioned you will have to attach the DSU to the 285. Also both the 7D's onboard flash and the 580 will have to be set to manual mode, no E-TTL. If you have any other EOS body besides the 7D then you will have to have the 580 on camera and again set in manual mode. You can't use E-TTL with DSU/285 because e-TTL uses a preflash that will trigger the slave unit before your shutter opens. </p>

<p>"You can't use E-TTL with DSU/285 because e-TTL uses a preflash that will trigger the slave unit before your shutter opens."</p>

<p>I think the Sunpak DSU-01 is suppose to account for the ETTL pre-flash.</p>

<p><em>"I think the Sunpak DSU-01 is suppose to account for the ETTL pre-flash."</em> - perhaps this could be possible with Canon's flashes?</p>

<p>I guess DSU stands for Digital Slave Unit in the DSU-01 model.<br>

Problem with digital slaves is that they try to guess number of pre-flashes from latest digital pre-flash based flash systems. Sometimes they are able to skip the preflash, and trigger on the final exposure stronger flash blast, but many times they do not guess right.</p>

<p>Some digital slaves have an adjusting slider or a switch and you must experiment how many pre-flash blasts to ignore, if your flash setup is simple, ... just try it.</p>

<p>Some pre-flash based systems, like Nikon CLS/iTTL produces a varying number or pre-flash light pulses that is needed for the multiple flash setup, and also depends on results of pre-flash testing, so in general, it is not possible to guess how many preflashes will be produced, to make a successful "digital slave" that is a passive electronic device and has no built-in prior knowledge of the flashing system protocol.</p>

<p>I would love to hear a better users experiences with digital slaves.<br>

At least my experimentation with digital slaves was not reliable, but possibly others have more chance, perhaps with Canon ETTL-II system and a simpler single remote flash setup ?</p>

<p>Thanks for the replies! I am using the 7d and will be giving it another go this afternoon. I will let you know if/how it works.</p>