Can I use 580EX for both master and fill

Scott_Quier

I've looked. I've searched. I can't find a reference to what I want to do.

Specifically:
[list\]
[*]Using two 580EX flashes
[*]One is on-camera and is the master and I want it to be fill as well, well call this 'A'
[*]Second, slave, not on-camera (obviously ), and this is 'B'
[*]Want a flash ratio A:B = 1:2
[/list]
It appears that 'A' will fire, but only to communicate with 'B' before the exposure. It doesn't seem to fire during the actual exposure. Flash 'B' is doing just fine.

Am I wanting to do something that the flashes are not designed to do.

I can get the 1:2 ratio if I take 'A' off-camera and use an ST-E2 to trigger the flashes and this would work for my purposes if I had a second assistant for my outdoor shoot tomorrow ... each assistant holding a flash while the ST-E2 is on the camera. I have just one assistant and she can't be in two places at the same time.

ziggy53

Scott,

Yes, I'm pretty sure it's just a matter of proper setup. I've done this with the Sigma units:

http://www.dgrin.com/showpost.php?p=557106&postcount=1

rwells

Scott,

Yes, you can easily do this. It's how I usually use two 580xx flashes.

* Make sure both master & slave are set to the same channel.
* The camera mounted "Master" always defaults to Group A.
* Set Master unit to enable "ratios".
* The off-camera unit should be set to Group B.
* Dial in the ratio that you like.
* This will allow you to use the on-camera flash as fill.

This is the method that Chuck Gardner uses with his two 580EX flash's setup like you are wanting to do. It has a lot of merit, and I've found this method to provide great results. I actually like this method better than how most people use two off-camera flash units.

Most usually set up their flash's in an inverted "V" lighting configuration (each flash at 45 degree angle to subject), and that's not really ideal. It lends itself to very strange shadows/highlights.

But, YMMV

Chuck's site is loaded with valuable information.


If your "master" on-camera flash is only outputting the pre-flash, then you have a C.Fn set so that it's only used this way. The default setting is to have the on-camera "master" unit, flash. I'm using a 5DMkII & 5D, so the C.Fn number might be different. Note that you can also enable the flash to only output the signal flash, not the main flash, on the flash unit itself. On the display, you will see an icon of a flash. If there is a lighting bolt flashing there, your flash is set to only output the signal. Keep pushing the "Zoom" button to change this. (I'm not looking at a flash while typing this, so it may be that you have to turn the "Dial" to change this. Not sure without looking at a unit)



Hope that helps...

Scott_Quier wrote:

I've looked. I've searched. I can't find a reference to what I want to do.

Specifically:[list\]
[*]Using two 580EX flashes
[*]One is on-camera and is the master and I want it to be fill as well, well call this 'A'
[*]Second, slave, not on-camera (obviously ), and this is 'B'
[*]Want a flash ratio A:B = 1:2
[/list]It appears that 'A' will fire, but only to communicate with 'B' before the exposure. It doesn't seem to fire during the actual exposure. Flash 'B' is doing just fine.

Am I wanting to do something that the flashes are not designed to do.

I can get the 1:2 ratio if I take 'A' off-camera and use an ST-E2 to trigger the flashes and this would work for my purposes if I had a second assistant for my outdoor shoot tomorrow ... each assistant holding a flash while the ST-E2 is on the camera. I have just one assistant and she can't be in two places at the same time.

Scott_Quier

rwells wrote:

Scott,

Yes, you can easily do this. It's how I usually use two 580xx flashes.

* Make sure both master & slave are set to the same channel.
* The camera mounted "Master" always defaults to Group A.
* Set Master unit to enable "ratios".
* The off-camera unit should be set to Group B.
* Dial in the ratio that you like.
* This will allow you to use the on-camera flash as fill.

This is the method that Chuck Gardner uses with his two 580EX flash's setup like you are wanting to do. It has a lot of merit, and I've found this method to provide great results. I actually like this method better than how most people use two off-camera flash units.

Most usually set up their flash's in an inverted "V" lighting configuration (each flash at 45 degree angle to subject), and that's not really ideal. It lends itself to very strange shadows/highlights.

But, YMMV

Chuck's site is loaded with valuable information.


If your "master" on-camera flash is only outputting the pre-flash, then you have a C.Fn set so that it's only used this way. The default setting is to have the on-camera "master" unit, flash. I'm using a 5DMkII & 5D, so the C.Fn number might be different. Note that you can also enable the flash to only output the signal flash, not the main flash, on the flash unit itself. On the display, you will see an icon of a flash. If there is a lighting bolt flashing there, your flash is set to only output the signal. Keep pushing the "Zoom" button to change this. (I'm not looking at a flash while typing this, so it may be that you have to turn the "Dial" to change this. Not sure without looking at a unit)



Hope that helps...

Thanks so much for the receipe. That's how I had it set and all I was getting from the master was the preflash. So, that really makes you last paragraph so appreciated. I'm now going to have a look at the custom functions and see where I goofed.