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Using more than one remote TTL flash

Discussion in 'Lighting Forum' started by nuclearboy, May 21, 2014.

  1. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA
    Hello,
    I have been using the Olympus FL600R with my EP5 as an off camera flash (TTL) with some success. (I have found that I need to bump up the Flash power +.3 or +.7 but that is another thread). Sometimes I need more light so I have invested in another flash, the Metz 58 AF-2. This should give me the power I need. I have the on camera flash or the FL300R for a trigger.

    My question relates to using the two flashes off camera in TTL mode. I have some idea how this works with one flash but is there anything special to know about using two flashes.

    Does one flash interfere with the other?

    With one flash, the metering and flash adjustment makes sense to me. With two flashes, I am not sure how things would work. How does the metering know how to adjust each flash or does it somehow just adjust them together?

    I am not sure if the question makes sense but I wanted to get some advice from those who might use two or more remote flashes in TTL mode in case there are some extra things to take into account.

    Thanks
     
  2. Sammyboy

    Sammyboy m43 Pro

    Oct 26, 2010
    Steeler Country
    ....... the 300-R is not a trigger flash, so use the pop-up flash in the camera. You can set up multiple flashes in the the 3 different flash groups in the camera. Each of the 3 groups can be set-up to trigger different flash EV. Each group can have multiple flash units, don't know if your Metz will work this way .......
     
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  3. Harvey Melvin Richards

    Harvey Melvin Richards Photo Posting Junkie

    Feb 15, 2014
    Southwest Utah
    What triggers the remote flashes? And how do these flash "see" the trigger? Is there a sensor that should face the trigger flash? I use a FL300-R as a remote, and it seems to work, but I have no concept of what is really happening.
     
  4. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA
    The on camera flash sends out a pre-flash which the other flashes can sense and understand. The remote flashes must see this flash signal. I find the sensor does not have to face the camera as it sees the reflected light. If you are far away, having the remote body facing the flash will help.
     
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  5. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA

    I see the basic settings for each group, and setting the different EV for each group. The Metz seems to support all of this too and it works well by itself.

    My question relates to this issue of flash power. What confuses me is how do you meter and control, from a single point (the sensor through the lens), the lighting power from more than one light source. In other words, how can the camera know where the light is coming from and which flash to tell to reduce power. Understanding the logic would help in setting things up and using the system.
     
  6. SpecFoto

    SpecFoto Mu-43 Veteran

    313
    Aug 28, 2012
    So Cal
    Jim
    As already mentioned, you can use up to 3 groups to assign each flash and then adjust the power for that group. The preflash measures the ambient lighting, determines camera settings and the flash contribution needed, based upon the power level you assigned to each group, and sends out an IR signal from the main flash to each group telling it to fire. All flashes in each group will fire at the same amount of power. The Olympus 600R manual refers to the RC mode for wireless control, don't be confused that this is radio control based, it is IR.

    So for example, say you set up a front flash, group A, in a soft box and a hair light, group B, behind the subject. If you do nothing to the flash power settings, each group will fire at 100%. The result will be way too much flash contribution, although properly exposed. So kick the front softbox down to 25 or 30% and the hair light down to 50-60% and you will get a halo of light from the rear with a small flash contribution from the front, and overall good exposure. The way you adjust the flash power is by using the flash exposure compensation button.

    There are numerous limitations to firing multiple flashes with IR signaling. Pretty much it is line of sight at approximately 30 degrees each side from forward and the IR window on the remote flash should be pointed at the main flash. Forget about firing flashes more more than 8 to 10 meters away, having lights behind the camera body, way off to the side, or around corners. And outside the IR is affected by the sun and in my opinion the IR system is pretty much worthless. For my 4 Nikon CLS speedlights I final invested in the Pocket Wizard TT5 system, which uses radio waves instead of IR and it works just great, is extremely reliable and with no line of sight limitations. Unfortunately there are no current radio based TTL flash trigger system for Oly or Panasonic, although some are rumored.

    If you really want to learn about flash, my suggestion is to to learn about manual flash. There are several manual radio trigger systems that can control multiple Oly flashes and fire them much more reliably than the built in IR system.
     
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  7. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA
    I was under the impression that I could use an Olympus Flash like the FL600R on the hot shoe as the trigger flash for other flashes but I cannot get this going.

    For instance, could I use an FL600R on the camera for ceiling bounce flash while also using it as the trigger flash for another FL600R set to some side with a diffuser. I am interested in doing this with the TTL settings.

    I have been using the remote system with the onboard flash of my E-P5. My question is whether I can use the FL600R on the camera so I have a more robust flash for the direct flash.
     
  8. biomed

    biomed Mu-43 Hall of Famer

    Aug 22, 2013
    Seattle area
    Mike
    Should work fine. Check out the Panasonic DMW-FL360L at B&H. It is currently $70 less than the identical (except for some cosmetics) FL600R. Both of these flashes are made by Panasonic and vary in price in respect to each other. Some time the FL600R is less expensive.
     
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  9. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA
    Thanks,
    I already have two flashes. My goal is to try and use one on-camera as the trigger to control the other one. Right now, when I use both flashes, I use the pop up flash as a trigger. I cannot figure out the settings to get the FL600R on camera to act as a trigger and thought someone may have this experience. The manual does not spell it out for me.
     
  10. Sammyboy

    Sammyboy m43 Pro

    Oct 26, 2010
    Steeler Country
    You have go to the SCP and the flash sub-menu. The bottom icon is for the flash that is mounted on the camera, your selections are OFF, M, and TTL. The next column to the right is where you adjust the power out-put.
     
  11. nuclearboy

    nuclearboy Mu-43 Top Veteran

    850
    Jan 28, 2011
    USA

    Thats useful. So the bottom flash, "D" is the one on the camera or hot shoe.

    My problem is that when I have the FL600R on the hot shoe, the slave flash does not fire. If I use the pop up flash, the slave fires in TTL remote mode. With the FL600 on the hot shoe, it does not seem to send the pre-flash that fires the remote slave.

    I am wondering now if that is possible. If it is, I am wondering what setting is needed for that.