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Are TTL and RC mutually exclusive?

Discussion in 'Olympus Cameras' started by Johbremat, Jul 9, 2014.

  1. Johbremat

    Johbremat Mu-43 Regular

    130
    Dec 5, 2013
    My understanding of TTL is that a pre-flash is sent out, the camera meters the scene and then automagically sets the flash appropriately. RC doesn't rely on this at all, does it? If I want to remotely command multiple FL-600R via radio rather than optical, and am happy to forgo TTL functionality then it's a non-issue, yeah?

    Or does the radio being used need to support TTL for RC to work?

    RadioPopper PX system (http://www.radiopopper.com/#!px/c18on) looks nifty. Works as a bridge. Doesn't state Olympus compatibility but may not be an issue.

    Everything else I've seen in the way of PocketWizards, Apurture, Cactus...leads me to believe they will only act as a trigger. There's not remote capability and you have to individually set the flashes which won't always be possible if they're strung up somewhere inconvenient.

    :confused:
     
  2. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    I don't think any radio control unit for Olympus will allow you to adjust flash intensity remotely, you can only do that with the OEM system. The Olympus system allows you to adjust each flash 'almost' independently from the camera. What you do is assign flashes to groups and the camera can control flash power of flashes assigned to those groups. It's very much how the Nikon system works. If you want to use radio control, you have to set each flash unit manually.
     
  3. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    I'm not sure if radiopoppers are the same as Aokatec, but they seem to work on the same principal of relaying the light signal via radio, and the aokatec worked on 4/3 (unsure about m4/3, but it should work). Thus the Radiopopper's should work, perhaps googling it might be a good idea though.

    http://www.aokatec.com/AK-TTL.html
     
    • Like Like x 1
  4. christofp

    christofp Mu-43 Regular

    138
    Jul 21, 2012
    I think you worry to much!!

    The optical trigger system is quite good. I have two Metzes and a fl600R (not to speak of the tiny flm-xx which came with the camera). RC mode and TTL work very good, even with third party flashes like Metz.

    Additionally HHS/FP mode works up to 1/8000s, all with RC and TTL.

    And you have 3 groups A,B,C and the on-camera flash as group D, which all can be adjusted separately in the nice flash SuperControlPanel.

    The only things you should know is that the Oly flash metering tends to underexpose by -0.7EV. Maybe the reason is that it is thought as a fill in where -0.7 seems reasonable. Don't know and it does not hurt, I simply cure it by setting +0.7EV for my fl600r (group A) and +0.3EV for my strong Metz flash (group B).

    Sometimes (long distance or bright light) my fl600r does not "see" the optical trigger, these are the moments I wish Oly or someone else would provide a TTL-capable radio trigger system. But as the flash/radio trigger has to communicate with the camera to tell its capabilities (RC, FP, TTL, min flash sync speed), a fully compatible radio trigger has to be quite intelligent which might still take some time to show up.

    in the time being, you can

    - use the quite capable optical trigger system
    - use a cheap or expensive manual radio trigger system
    - or use a hybrid system like the one from Akoatek where a flash is used on camera to tell the camera what is needed for the remote master and an optical receiver transmits the flash pulses as radio signals to the remote slaves.

    Christof
     
    • Like Like x 1
  5. Johbremat

    Johbremat Mu-43 Regular

    130
    Dec 5, 2013
    No doubt. I'll be using three flash units that will each be assigned to a group on their lonesome. Just hoping I can use the RC options on-camera to modify their output remotely.


    Been Google-bashing for the last week trying to suss it. Also left inquiries on the RP FB Page and their inbox.

    Looked at the Aokatec and they may work, but just don't seem very elegant in execution. No reason they won't work with m4/3 gear as the protocol hasn't changed. But just to try out the PX system in hoping?

    Seems an expensive exercise.

    (Wonders if :43: wants to chip in to see if they're a workable solution :tongue:)
     
  6. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    But you're talking about flash units that are dedicated to Olympus cameras, not aftermarket radio triggers like Pocket Wizards etc, these are two completely different things.
     
  7. OzRay

    OzRay Mu-43 Legend

    Jan 29, 2010
    South Gippsland, Australia
    Ray, not Oz
    If you're using Olympus wireless flash units, or any other brand that is fully compatible, then you can control them very easily from the camera. The system is really easy to manage, as long as you mark your flash units regarding which group they belong to and then use them for the configuration intended. What I mean by that is, set one lot of flash units for background lighting, another for main illumination and others for anything else, and always use them for those configurations. You will never have to worry about flash setup again.
     
  8. christofp

    christofp Mu-43 Regular

    138
    Jul 21, 2012
    OK, yes.

    I was misleaded by the title but by reading the latest answers I understand that it is all about radio and TTL.

    I hope the RadioPopper system provides similar good functionality as the Aokatec one does, but I don't know.

    But most preferable solution would work without the need for a transmitter+master flash, instead radio master only. I hope we will see this soon ...
     
  9. Johbremat

    Johbremat Mu-43 Regular

    130
    Dec 5, 2013
    Don't worry chief: you're on the right track.

    Looks like expensive exercise it is: buy into PX and see if it'll recognise the pre-flash output and if so, the receiver should hopefully translate the signal without too much issue.
     
  10. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    I don't understand how one is less elegant than the other, they are functionally identical as far as I can tell?

    Both have a sensor which detects the preflash, convert it to a digital signal, send it out via a radio, then converted by a receiver and resent via an LED to the flash.

    With both you need to cover your flash in tape/foam to stop the preflash from the camera being seen, only the flash from the LED needs to be able to get through or it can flash twice.
     
  11. Johbremat

    Johbremat Mu-43 Regular

    130
    Dec 5, 2013
    The PX TX measures the electromagnetic pulse emitted from the flash as a result of pre-flash. Sits on top or beside the commander and doesn't require line-of-sight.

    The PX RX Canon mount looks to marry up with the FL-600 sensor and sits nicely in front of the flash's body. Doesn't require being jerry-rigged to the device.
     
  12. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    You are aware that this is purely marketing bull**** and it just looks for IR light? An "electromagnetic pulse" could be visible light, it could be infrared, it could be radio waves. They're all actually the same thing at different wavelengths/energies... (gamma rays, very high energy/short wave UV etc, ionizing radiation basically are generally excluded... not always though)

    If you ever buy one, do a test for me. Cover the "Electromagnetic sensor" window on the front of it with tape and take a picture, it won't function. Take a picture with the flash head completely covered so no light gets out, it won't function.
     
  13. Mikefellh

    Mikefellh Mu-43 Top Veteran

    939
    Jun 7, 2012
    Toronto, Canada
    Olympus' RC (flash Remote Control) doesn't use radio...it uses visible flashes to send commands to other Olympus "R" flashes (FL-36R, FL-50R, etc.). You can tell these flashes to be TTL, FP-TTL, auto, or manual, all set via the RC screen on the camera. The camera uses the flash that's transmitting the pulses to measure the light.


    Most wireless triggers are designed to be used with manual strobes, which don't use TTL communication.

    The only one I know of (but haven't tested myself) that is compatible with Olympus TTL is from Aokatec:
    http://www.aokatec.com/AK-TTL.html

    (Added later)
    Only thing about the Aokatec unit is it still uses the pulses of light from the camera's internal flash, which are then repeated via radio to the receiver(s), which then send pulses of light to a device you attach to the remote flash's light sensor. So you still have to use Olympus' RC mode on all devices (both the camera, and receiving flash units). Unlike other brands it doesn't use the hot shoe to transmit (but again this is the only one that seems to work with Olympus TTL). Suggest watching the instructional videos on YouTube to understand how this works.