The 7d infared wireless trigger (or any infared trigger for that matter) is not meant to be used in direct sunlight. If you are using it on a somewhat cloudy day you might see improvements but dont expect too much from it if you have ample amounts of natural light. Also infared is not meant to go very far. I think 5-6 feet is right around where it starts losing it effectiveness.

So your alternatives to that…..

At the most expensive end is PocketWizards. (Radio frequency is your friend – Espically if you do a lot of outdoor portrait work and you need consistency in your flash) Also with ETTL capability.
Next level down (but still quite expensive) is Radio Poppers. (again Radio frequency) Also with ETTL.

Then all the way at the bottom of the expensive ladder is Gadget Infinity Cactus V4′s or V6′s. I have the V4′s (also Radio). While these are a lot less expensive than the other 2 mentioned above there are a few drawbacks to these. No ETTL. Everything is Manual (which isn’t all bad since you get more consistentcy in your flash). They are pretty cheap looking, which is what you might expect for $60 wireless triggers. And you do get an occassional misfire or two. But no problems with sunlight since it’s not infared.

I don’t use them a whole lot so I couldn’t justifiy the $400-500 price tag on the Pocket Wizards.
For $60-$70 the Cactus V4′s or V6′s might be worth a shot for you!

is the 7d internal wireless trigger not sensitive enough during outdoor especially?
I have been trying to shoot with 2 units of 580Ex2 with 7d for outdoor portrait, 1 on the left and 1 at the back of the subject but it seems cannot be triggered sometimes, not stable and sometimes it flashes but sometimes it cannot be flashed.

Hope you guys can help me , is there any ways to solve this? or the speedlight need to face each others when detecting the trigger?

How did you get the pictures of the various menus from the back of the camera? Did you just shoot them or there is some special trick akin to capturing a screenshot. Any help would be greatly appreciated

But I do Have a question or two. You stated that you were using the 7D’s pop-up and wireless feature to control your EX off-shoes. Isn’t the wireless feature on the 7D an IR or Optical trigger? How were you able to communicate with the flash that was behind the subject if it was out of “line-of-sight”? Also, You didn’t mention which EX flashes you were using?

Thanks – I’ll carry on using the Elinchrom units I have then! So close Canon yet so far

Paul

Transmitter sits in the hot shoe, recievers on the strobe. Viola’