T3i: can I fire wireless flash only without built in flash?

Just got my T3i today and wanted to use my 580ex flash wirelessly. Problem is, the only way I can seem to get it to fire is if I flip the built in flash up as well. I've been fiddling around with the settings and there is an option with a little icon which says I should be firing my 580ex only but that doesnt seem to be the case. Worse comes to worse I'll just ghetto mod it and stick something in front of the built in flash to block the light.

thats how it talks to the other flash is through its own output, if setup the light emmited from the on cam flash is not ehough to undermine the off cam flash. so if you block it it will block the wireless feature of the flash

You'll need a wireless transmitter and receiver to just fire the off camera flash.
Or you may be able to get a remote thing to go in your hot shoe wired to your flash.

stukovx wrote in post #12438839
Just got my T3i today and wanted to use my 580ex flash wirelessly. Problem is, the only way I can seem to get it to fire is if I flip the built in flash up as well. I've been fiddling around with the settings and there is an option with a little icon which says I should be firing my 580ex only but that doesnt seem to be the case. Worse comes to worse I'll just ghetto mod it and stick something in front of the built in flash to block the light.

Does the pop up flash contributes to the exposure? normally it shouldn´t be the case, I´m not that familiar with Canon´s system (used it only a couple of times but with a 1D MKIII and a ST-E2) but check out your user manual to see if there´s such an option.

Some people use a piece of exposed film.

stukovx wrote in post #12438839
Just got my T3i today and wanted to use my 580ex flash wirelessly. Problem is, the only way I can seem to get it to fire is if I flip the built in flash up as well. I've been fiddling around with the settings and there is an option with a little icon which says I should be firing my 580ex only but that doesnt seem to be the case. Worse comes to worse I'll just ghetto mod it and stick something in front of the built in flash to block the light.

If you choose the right option, the T3i flash has almost no output when it triggers the slave flash. What "problem" are you experiencing?

If you shoot into a mirror, or wide open at close range and high ISO, you will see some of the light from the trigger flash.

Indoors you can deflect this light and it will bounce off the surrounding areas and still reach the slave.

One of the wireless settings on the 60D (probably the same on the T3i) has an image of the pop up flash: remote flash. You can select that to have just the popup flash, both flash, or wireless only flash.

Even on the wireless only mode the popup looks like it flashes, but that is the trigger flash before the actual exposure.

You can also blance the flash power between the popup and wireless. I like to use the wireless flash off to the side a bit, then dial down the exposure compensation for the pop up to add some fill light.

That communication flash is not bright enough contribute to the light in the image at all; it is ONLY enough to get the information from your camera to the flash to trigger it appropriately.

If you need longer range, or to trigger remotely in high ambient light conditions, you'll want to get a radio trigger of some sort.

On my 60D, and I presume also the T3i, the pop-up will trigger my 430EX wirelessly from at least 25 feet away even outdoors with sun on snow. I did the test back in February, and the remote flash fired every time from that distance as long as there was line of sight. Line of sight is not necessary inside in moderate sized rooms, as reflections off walls and ceilings will trigger the external flash effectively.

As others have said above, the pop-up produces far too little light to affect exposures if you set the camera to wireless only. The pop-up can produce modest amounts of fill light if you set the camera to (wireless + pop-up).

ahhhh, thanks for all the input everyone, I didn't know the built in flash used a flash to transmit the signal. I thought it would do so without flashing. I'll give it a try and see how it turns out.


Thanks!