# Light metering with multiple flashes



## Dholai (Feb 5, 2014)

Hi all,

This is my first post even though I have been coming to this forum religiously everyday for a few years now.

I have a question please.

How do you set up to do light metering with an external light meter(e.g. Sekonic 758) when you use multiple flashes?

In studio, I use a sync cord connected to the meter and one of the strobes, which then fires other strobes optically and I get my reading.

Can the same be done with flashes? 

How can you use the ST-E3 RT to do this ? Can I connect a cable to it and the light meter and fire multiple 600 Rts to get a reading.

The ST E3 manual does not mention anything. Search with Google did not turn up anything either!

Please help.

Thanks a lot

Dholai


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## Sella174 (Feb 6, 2014)

Well, being unfamiliar with modern flash technology, in the old days we did it through manual calculations.


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## Jim Saunders (Feb 9, 2014)

Dholai said:


> Hi all,
> 
> How do you set up to do light metering with an external light meter(e.g. Sekonic 758) when you use multiple flashes?
> 
> Dholai



Two angles on this:

1. If you want to set the power on your lights manually and fire them to check the output with your meter, the ST-E3-RT will do that just fine as long as it is off the camera.

2. Another possible approach is Ext-A; it seems to work pretty well, I had two pairs on opposite sides of a dimly lit dirt arena set to figure it out for themselves and got the photo below. It's a suggestion, I'm all for learning more from others here too.

Jim


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## privatebydesign (Feb 9, 2014)

If you are using a 1 series camera it actually has a flash meter built in, just use the FEC button to take a flash reading and adjust exposure, in either M or Av modes or to the flash power level, as per the bars in the viewfinder.

However I don't know anybody that ever uses this feature, they just guess and chimp.

Yes the Sekonic will work exactly the same as with studio lights though you don't connect a cable to it, the ST-E3-RT does not need to be on camera to work, just walk with it in your hand, and the Sekonic in the other, push the test button and the 600's will fire, adjust the power as you want on the 600 and re test fire until happy, then put the ST-E3-RT back on the camera.


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## Dholai (Feb 9, 2014)

Jim/PBD,

Thanks for the replies.

I need to fire the flashes from my meter so that it can meter the incident light. How do I do that ? 
I was thiking to connect the ST-E3 to the Sekonic with a PC to mini stereo cable and push the trigger on the sekonic to ask the ST-R3 to send commands to the flashes to fire.

Question is, will it work and what cable I need ? The N3 ? What cable the ST-E3 RT takes that has a PC sync terminal at the other end?

Thanks

Dholai


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## privatebydesign (Feb 9, 2014)

I don't believe that would work, the socket on the ST-E3-RT is an output, not an input, it is there to trigger a pre 2012 body as they cannot be remote released via the hotshoe, post 2012 cameras can. It might trigger it, but I wouldn't risk being the first to try with mine 

But you don't need to connect the ST-E3-RT and the Sekonic to get your flash metered, just use the Sekonic in "cordless flash mode", the first of the three flash meter icons (as arrowed below), and fire your flash via the ST-E3-RT. This will give you accurate incident readings and you can do it by having the Sekonic in one hand and the ST-E3-RT in the other.


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## digital paradise (Feb 10, 2014)

Dholai said:


> Hi all,
> 
> This is my first post even though I have been coming to this forum religiously everyday for a few years now.
> 
> ...



I have a Sekonic L-358, 3 600's and an STE3. I contacted Sekonic to see of they were ever planning on creating Canon friendly RT module. It appears not as they are in bed with Pocket Wizard. 

If I am working with my 3 flashes in a studio set up they are usually on manual. I use group mode which is just awesome. I carry the STE3 and L-358 around with me. I turn off the other flashes and work on one at a time starting with the key. I fire the flash using the test button, get a reading on the L-358 and adjust power output using the ST-E3. When all done I place the STE3 back on the camera. 

This was the only wireless solution I could find. I purchased a generic spare foot to carry the STE3 around but I found it was very tight while clamping so I cut up the foot that came with the flash to prevent damage. I ordered a replacement foot from Canon.


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## Dholai (Feb 11, 2014)

PBD and all others,

Thanks for your time.

I think I found the solution, what you both suggested.

Cordless flash setting for Sekonic in one hand , ST-E3 -RT on the other hand, 600 RTs in there respective places with one as main light and meter just the way I meter my strobes.

Will try it outdoor and see if I can make it work. 

BTW, it will be used with a 1Dx

Thanks again

Dholai


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