My 7D wireless flash only sometimes triggers the my off-camera speedlites. Help me please!

[ralph_nguyen]

<p>Hi all,</p>

<p>So I have a 7D and I'm trying to use it's built in wireless flash system. I have 580 EX II and a 430 EX II that I use on light stands with umbrellas, that I have both set to Channel 1 slaves, and have made sure that they are on different letters. So, I pop up my internal flash (as I need to so my camera knows to use flash), and only sometimes do my off-camera flashes go off. I have flicked on the setting so that only my speedlites would trigger and not my on-camera flash.<br>

When I go to flash settings and hit the "Test flash settings" trigger, my on-camera flash flickers but only sometimes my speedlites do.<br>

BTW, this is a recent problem.<br>

I've tried changing the channels...<br>

I've tried changing the batteries.. <br>

I don't know what to do at this point. I know it's probably user error on my part. Can you guys help me figure out what I'm doing wrong or give me pointers on how to make it work? Thanks!</p>

[PuppyDigs]

<p>I've used a ST-E2 to trigger 550EX and 430EX Speedlites for many years and it's been utterly relieble.  I find it ideal for macro where my trigger distance is close. Great for carrying into jungles and shooting small plants.</p>

 

<p>The problem with an optical trigger like the ST-E2 or 7D popup is you have to work within its limitations: line of sight, 15 feet and away from bright light. If something blocks it or you exceed range you start having problems. If you shoot larger sets you really need a radio trigger.</p>

[steve_dunn2]

<p>I haven't had any problems with this - but I've only made limited use of this feature, and typically not in situations that are likely to be challenging to the communication system.</p>

 

<p>As Puppy points out, you're counting on the relatively weak pop-up flash to transmit all of the commands to the slave(s). You're not going to be able to control a slave at a dreadfully great distance, particularly if there's a fair bit of ambient light. If the slave's sensor isn't pointed more or less directly at the camera, that cuts the range even further, as you're counting on light bouncing off other surfaces with the light losses inherent in that. And so on.</p>

 

<p>Beyond that, I can't really help you much.</p>

[paul_russell1]

<p>Are you using the swivel head facility to have the sensor facing the approximate direction of the camera?<br>

This is especially important outdoors. The flashguns have to see the light, so the trigger flash from the camera needs to be able to bounce off of something or preferably have line of sight between the flash pick up and the camera flash.<br>

For what its worth I have found the optical flash commander of the 7D works more reliably and over greater distances than my STE-2 ever did, the only thing I miss about the STE-2 is the less intrusive IR trigger and the AF assist, it's the horrible strobe type on the 7D.<br>

Getting better pictures though.</p>

 

[jeffrey_c1]

<p>Ralph,</p>

<p>Take a look at this site:<br>

<a href="http://www.digital-photography-school.com/how-to-control-multiple-flashes-wirelessly-with-a-canon-7d">http://www.digital-photography-school.com/how-to-control-multiple-flashes-wirelessly-with-a-canon-7d</a></p>