Hey Folks,
I mostly shoot video but it was fun practicing portraits with my 60D. I just learned I can use the in camera flash to control an external flash. All I have is a Canon Speedlite 550EX it doesn't have any channels but it has a slave mode. I set the camera on TV, enable Flash Firing, Flash mode E-TTL II 1st curtain, Evaluative, wireless function is the middle diagram that I think is external only, Firing group is all. Works great for this new guy but is there a way to program it to where only the external flash fires? When I put the internal flash down, nothing fires. Leave it up? they both fire. Hope somebody can mention a way or is it because my flash is kinda outdated?

Thanks
Art

No, to fire a slave without the internal flash firing you have to use the Canon wireless transmitter that goes on the hot shoe.

My 7d works the same way. You have to use the internal flash for the external to trigger. You can go in and reduce the flash power to minimum though.

Ahh. Good call. I'll Dull the flash a bit and try it again. Would be nice to be in a position to purchase a wireless transmitter, not at the time.

Thank you
Art

Are you concerned that the internal flash is adding to the total lighseeThoreau image, or is there a reason why you don't want the internal flash to go off at all? With the setting you described in your post, the internal flash only fires to trigger the external flash, but it occurs before the curtain opens so it doesn't contribute to the light in the image..

The "flashes" you see on the internal flash occur _before_ the shutter is open. That's how the camera communicates with the other flash. Regardless of whether the internal flash contributes to the final image, it needs to send out that series of flashes/light pulses to tell the slaves what to do.

Ok,
Yes, I thought that the internal flash would add to the overall lighting of the subject. Am I understanding that I flashes to activate the slave and before the shutter opens?

Thanks!
Art

Correct. Internal flash will trigger your Speedlite, but prior to the shutter opening. Thus there will not be any additional light spill. Try it out, it should work.

Works good. Thanks!
Art