Two Speedlite set up Sync question

Hey all,

I was doing some testing yesterday and soon realized what I imagined working, won't work.

I've got a 7D and two speedlites, a 420 & a 430 exII. I wanted to set the 420 up on a stand as a back light source and use the 430 to trigger it, since i can control the power on the 430. Well that didnt work until I took the 430 off the camera and I know why, because the 430 wont act as a master.

So my question is this, if i get the cowboy studio transmitter/receiver can I then use the flash set up as i want to?

I'm looking to use it for wedding receptions, so i wont need control of the back light flash, just the on camera flash to bounce or control as needed.

Thanks!

You can set up wireless flash on the 7D. It uses the built-in flash to control Speedlites remotely complete with ETTL functionality. The built-in flash can be set to just emit a control signal or actually give some flash light as well. You can set it to control several Speedlites in groups. The 430 will act as a slave flash, not sure about the 420.

The 420 wouldnt be much use with the cowboy trigger as it doesnt have manual controls so it would fire full power every time. ( and by the way why get that trigger system? There are better options)

Thanks Mike,
I am aware the 7D can trigger them, my only concern is being across a room and it not seeing the flash. Plus I thought by putting the 430 on camera it would still trip the 420 as a slave, but it wont, I would need the 580 to do that, as I just found out.

The 7D wireless-- as far as i can understand is only by line of sight. If the IR is blocked by anything it won't work.

nmphoto wrote in post #12016829
Thanks Mike,
I am aware the 7D can trigger them, my only concern is being across a room and it not seeing the flash. Plus I thought by putting the 430 on camera it would still trip the 420 as a slave, but it wont, I would need the 580 to do that, as I just found out.

The 580 would have the same limitations as the built in controllers "across a room" as they are both visible light emissions and require line of sight.

Gonzo,

Correct, thats what I want it to do, just a background fill flash from across a room that will give out key light from behind while i fill in from the front with my controllable 430.

gonzogolf wrote in post #12016843
The 580 would have the same limitations as the built in controllers "across a room" as they are both visible light emissions and require line of sight.

Absolutely. The 580 is not necessarily going to be any better. Don't rule out the wireless function of the 7D so quickly. Do some tests. I have found that the signal works right across sizeable rooms even without direct line of sight. The signal bounces off walls, you know.

Right on, what I really wanted was to use the 430 to control the fill in flash & trigger the 420 on camera while having the 420 be the key light from behind, I could still technically do it off camera and retain the 7D's transmit firing.

nmphoto wrote in post #12016848
Gonzo,

Correct, thats what I want it to do, just a background fill flash from across a room that will give out key light from behind while i fill in from the front with my controllable 430.

Yes, but in your initial scenarios your 420 would have been controlled in ETTL mode (had you a master flash) and with the radio triggers they are a crippled manual.

If you want powerful front lighting you can use the 7D built-in flash to trigger (with ETTL control) a Speedlite held just above or to the side of the camera PLUS another Speedlite behind the subject. You can alter the ratio between to 2 Speedlites. It's all in the manual.

Do some tests!

Im no pro but I dont see anything wrong with the Cowboy studio setup. If youre learning and dont want to spend the money for something "nicer", they work great. I have three transmitters (two backsups) and three recievers. Ive heard of them stopping working etc but since backups are so cheap, what the difference? They work great in bright sunlight and I get a good 30 ft range out of them. They also dont need line of sight. (though range is smaller without an open view) A set of 1 transmitter and two receivers can be found on ebay for around 35 bucks!

Cool, Thanks Mike! I'll tinker more

Feasibility here depends a lot on how far it is "across the room"?
Five meters? Ten? Fifteen?

If it's not a grand ballroom, the flash light based control often works pretty well.

well it remains to be seen how big the rooms will be. I don't think I have any receptions being held in a large venue yet. i've seen some pretty cool shots of receptions using this method, so that was my approach heading into several weddings I have coming up.