ETTL - 2 flashes question

When I use my strobes I meter each separately to set my ratios for exposure. I think I know the answer to the following question, but want other opinions.

I'm trying to get a little more comfortable using my 580EXII. I can set it to Manual, meter (Sekonic L308s), adjust the power, and set the camera to those settings letting the 580 provide the light. I can meter for ambient, set camera to that, and use ETTl to provide fill. I think I'm pretty straight so far.

I had a old Vivitar flash setting around and got a optical slave to fire it. I tried a few test shots with the 580 set to ETTL and the Vivitar set to different power settings. That seemed to really throw the exposure off, like the 580 wasn't firing. Am I right to assume the 580 was reading the flash from the Vivitar and providing very little light itself? I'm guessing in this situation it'd be best to set both flashes manually and meter like I do my strobes.

Thanks for any help.

Wow you have a lot of confusing statements but lets try to sort it out. First in order to use ETTL you must have a compatible flash attached to the hotshoe of the camera. This flash can be a stand alone flash set to ETTL or a Master flash with the wireless mode set to ETTL with any accompanying slave flashes set to ETTL. The camera measure both the ambient light and also takes a meter reading from a preflash of all the flashes set to ETTL, whether one or many, to get a flash exposure. It then sets the output of the flashes set to ETTL.

Now lets look at what you are trying to do from what I can gather. You want to mix ETTL with manual. First any manual flash or non compatible flash is not going to be metered during the ETTL metering. Second most optical slaves fire when they see a preflash so that when the actual exposure is taken the optically slaved flashes do not fire. Third it is possible to mix ETTL flashes with manual flashes but you must be careful where and how you use your manual flashes. If you are trying to use them to provide the exposure for your main subject you are going to have issues.

From what I am reading you are not using ETTL anyway. If your optically slaved flash is firing during the exposure then you do not have any preflashes. If your 580EX is set to manual and your Vivitar is manual then you are manual and there is no ETTL. If you are waiting for the camera to set your flash output for your 580EX then you will waiting a long time. In order to use ETTL you need to attach your 580EX to the camera and set it to ETTL mode. When you do that then your Vivitar will not fire, during the exposure, because it will have already been fired when the camera had the 580EX fire a metering preflash.

With what you have my suggestion is to just use your flashes in manual mode and forget trying to mix ETTL. It sounds like that is what you are doing anyway so I am a bit confused about the ETTL and how you are trying to use it when you say that your 580EX is set to manual. When your flash is set to manual mode then you have to set the flash output for that flash. In order for the camera to set the flash output in ETTL mode your flash must be an ETTL compatible flash and set to ETTL. As I mentioned above it must also be attached to the hotshoe of the camera, either directly or with an "Off shoe" cord, or it can be a "slave" flash set to ETTL when using Canons wireless system.

agv8or wrote in post #10766647
Wow you have a lot of confusing statements but lets try to sort it out. First in order to use ETTL you must have a compatible flash attached to the hotshoe of the camera.

Sorry for the confusion and am aware to use ETTL you need a compatible flash attached to the hotshoe. My 2nd paragraph is merely 2 situations where I'm fairly comfortable using my 580EXII. #1 - using my light meter to get the power (manual setting) of the flash for the manual settings on the camera I want. #2 - measuring for ambient, setting camera to those manual settings and set the flash to ettl mode to provide the fill.

agv8or wrote in post #10766647
Now lets look at what you are trying to do from what I can gather. You want to mix ETTL with manual.

Yes, that is what I was attempting.

That explains what I was seeing. I could tell the Vivitar was firing, but it wasn't showing up in the image. It was firing at the preflash and not being recorded on the image.

Not much, but trying to learn the 580 a little more. Of course, I don't have to worry about ettl when I'm using my White Lightnings .

Yeah, I think if I'm gonna use more than one flash that manual on both is the way to go. That way I control the lighting and can set the ratios like when I'm using my WL's. I think I may play around with ettl using the 580 only and in the camera hotshoe.

Thank you for the help.

You can mix ETTL with manual it is just going to cost you a little more money than the way you are trying to do it right now. You can add some more Canon Speedlites and using the wireless system use some flashes in ETTL and then override ETTL on one or more Slave flashes by holding the mode button for a few seconds. You can also buy into the ETTL compatible Radio Popper or Pocket Wizard systems.

agv8or wrote in post #10767837
You can mix ETTL with manual it is just going to cost you a little more money than the way you are trying to do it right now. You can add some more Canon Speedlites and using the wireless system use some flashes in ETTL and then override ETTL on one or more Slave flashes by holding the mode button for a few seconds.

While there may be another 580EXII somewhere down the road, right now I'm good with with the flashes I currently have.

No thanks, I'll stick with my Quantum Radio Slaves .

Thanks again for your help. ETTL is just not that important to me when using multiple flashes, so I'll stick to trying it when the 580 is on-camera and the only flash.

agv8or wrote in post #10766647
Wow you have a lot of confusing statements

I must be reading different then you then

D Thompson wrote in post #10766348
I'm trying to get a little more comfortable using my 580EXII. I can set it to Manual, meter (Sekonic L308s), adjust the power, and set the camera to those settings letting the 580 provide the light. I can meter for ambient, set camera to that, and use ETTl to provide fill. I think I'm pretty straight so far.

Yes.
I don't think an L308s can meter ambient - flash ratio like a L358 can?
That would be even easier

D Thompson wrote in post #10766348
I had a old Vivitar flash setting around and got a optical slave to fire it. I tried a few test shots with the 580 set to ETTL and the Vivitar set to different power settings. That seemed to really throw the exposure off, like the 580 wasn't firing. Am I right to assume the 580 was reading the flash from the Vivitar and providing very little light itself?

Yes.
The ETTL preflash will trigger the vivitar "prematurely" (before the actual exposure), thus throwing off the ETTL metering.
Additionally, the Vivitar probably isn't fully recharged when the "actual" flash comes, so in that case isn't able to flash again at required power.

AFAIK, there are some optical triggers that prevent this by ignoring the preflash.
Edit: Yep: http://www.adorama.com …hinfo=wein+digi​tal+slaves

From this page: http://speedliting.com …-triggers-radio-infrared/

D Thompson wrote in post #10766348
I'm guessing in this situation it'd be best to set both flashes manually and meter like I do my strobes.

Yes.
No preflash & fixed output from the 580EX.
I use it sometimes with my Lumedynes.

René Damkot wrote in post #10770855
I must be reading different then you then

Thanks.

I don't think an L308s can meter ambient - flash ratio like a L358 can?
That would be even easier

Yeah, the L308s is pretty basic. May need to check the L358 out.

The ETTL preflash will trigger the vivitar "prematurely" (before the actual exposure), thus throwing off the ETTL metering.
Additionally, the Vivitar probably isn't fully recharged when the "actual" flash comes, so in that case isn't able to flash again at required power.

AFAIK, there are some optical triggers that prevent this by ignoring the preflash.
Edit: Yep: http://www.adorama.com …hinfo=wein+digi​tal+slaves

From this page: http://speedliting.com …-triggers-radio-infrared/

I'll have to see how the Quantum 4i's do. The sender would be in the hotshoe with a pc cord to the 580 and hook the Vivitar up to a receiver. It'd probably still be better to use manual settings if using more than the 580 in the hotshoe.

Thanks Rene'