Canon 7D wireless flash...

Do I need a straight line of sight to fire a 580EX from a 7D wirelessly. Or... can I fire the flash then it is attached to a flash bracket which keeps the flash over my camera?

Second question (two for the price of one). Is the IR wireless flash efficient outdoors during bright sun? Also how far between camera and flash before I lose contact?

RPCrowe wrote in post #12105533
Do I need a straight line of sight to fire a 580EX from a 7D wirelessly. Or... can I fire the flash then it is attached to a flash bracket which keeps the flash over my camera?

Second question (two for the price of one). Is the IR wireless flash efficient outdoors during bright sun? Also how far between camera and flash before I lose contact?

The 7D communicates to the remote flash via optical signals from the onboard flash. It's better if you use a cable if the flash is just going to be on a flash bracket.

A straight line of sight is needed if there's nothing to bounce from. This typically happen outdoors, or in very large rooms. In a normal living room, you can hide the slave under a sofa and it will still fire.

The sun will easily overpower the light pulses from the flash on the 7D, if the sun hits the receiver on the slave flash. The pulses aren't IR, by the way, not when using an ordinary flash as a master. I have on some occasion made a "receiver hood" out of some cardboard, which I taped on the slave flash.

The range depends upon how dark it is around you. If it's really dark and you have a direct line of sight you may find that it works at ranges of 15 to 20 m.

I think you'd find an off-camera shoe cord (OC-E3 or $20 ebay equivalent) to be a lot more predictable and consistent than the 7D's pop-up fash as Master for the speedlite on a bracket.

It'll probably work when the pop-up's control flashes have something to bounce/reflect off of.

Outside... definitely needs line of sight.

I've tried holding a slave beside the camera. Even outdoors, it will actually be triggered when held far enough to the side, at arm's length, that it's not visible in a picture shot with a 10 mm lens on the 7D. Just aim the receiver towards the camera.

I hold my 580 above or to the side, frequently, when playing around with it.

Unfortunately, even a reasonably bright room will overpower and "lose" the signal. If you plan to use it outdoors or other bright conditions you'll want to look into radio triggers or a long (enough) OCF cable.

RPCrowe wrote in post #12105533
Do I need a straight line of sight to fire a 580EX from a 7D wirelessly. Or... can I fire the flash then it is attached to a flash bracket which keeps the flash over my camera?

Second question (two for the price of one). Is the IR wireless flash efficient outdoors during bright sun? Also how far between camera and flash before I lose contact?

My 580ex II works so well with my 7D's wireless. I don't need LOS indoors, it can be facing some other direction and still fires perfectly each time. Outdoors it has also worked flawlessly for me.

Indoors it's fairly easy....in direct sun? Not so much. I'll usually have someone or use something to shade the sensor. Seems to work much of the time.

CactusJuice wrote in post #12105950
My 580ex II works so well with my 7D's wireless. I don't need LOS indoors, it can be facing some other direction and still fires perfectly each time. Outdoors it has also worked flawlessly for me.

+1 Though using the 60d here.

I have received my 7D and can now play with the wireless flash capability. I used it indoors in a normal sized room on a bracket and it works great. In fact when bouncing a hotshoe flash, the onboard flash at about a 1:4 ratio makes a fairly nice fill. However, as with any use of the onboard flash, it is severely restricted by the size of your lens hood. Larger lens hoods tend to leave a dark shadow at the bottom of the frame.

I experimented with the 7D firing the flash on a bracket outdoors...

I tried the flash outdoors without any close up subject in the frame and it worked fine if I was shooting with my back to the sun. However, without a closeup subject in the frame, the 7D would not fire the flash when shooting into the sun.

However, when I placed a subject 6-8 feet from the camera, the flash would fire. I assume that it is the feedback from the onboard flash reflecting from the subject that fired the hotshoe flash.

I have a lot more work testing this concept regarding subject distances, angles of the sun, etc.

I have an off camera sync cord but, it might be easier to shoot just using the 7D as a controller. Well, we'll see.

I also need to experiment to see if the 7D can sync my studio strobes through their optical slaves.