need a little off camera flash guidance,

Discussion in 'Lighting Forum' started by genesimmons, Jan 9, 2018.

  1. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    hi all, recently picked up a godox tt685 and a godox x1t0 ttl trigger, i am very new to off camera flash and flash in general, i think i have things set up correctly and it seems to work but with everything in ttl mode i dont see the zoom mm go up and down on the flash like i do when its on the camera, i have channel a set to ttl on the x1t0 and the flash is set to ttl, flash seems to trigger fine but no matter what zoom i use it doesnt go up or down on the flash, its in zoom auto and its at lowest on the dial which is the 3 bars, any one using this combo? on a em1.2. also i see a olps on the flash that i have not seen before, need to search for the flash manual maybe, haha, hoping some one can steer me in the right direction
     
  2. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    Not certain / pure speculation here, but it may be that way because the flash is off-camera. The zoom setting on the flash is meant to direct the cone of light based on the FoV of the lens (i.e. the focal length). But, because the flash is off-camera, this is no longer a point of concern.

    I'm not certain how my FL-50r's work when off camera in TTL mode off the top of my head, but I'm pretty sure the zoom setting goes away. I know that it does even when I have the flash mounted in the hot-shoe, but have the head angled up for bounce. It's only when I rotate the head down facing towards the subject that the focal length shows up.
     
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  3. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    I believe @ijm5012@ijm5012 is correct. When off camera your flash shouldn't zoom automatically in and out with your camera lens, as that Field of View (FoV) measurement for the flash is only correct when its on the camera. (well, that is if godox fixed it's auto zoom problem, it's a tad bit tighter than it should be imo.)
     
  4. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    ahh yes i could see that but then why is it or is it important to have ttl off camera? i have my flash set to the side of the subject and when i zoom in or out i thought it would increase or decrease the flash output acordingly as it does in ttl mode on camera, so in ttl mode off camera nothing changes? then theres no point of being in ttl mode may as well be in manual and test the exposure, i tried with the flash pointing straight out and with it pointing up as a bounce flash and still no difference, i am pretty sure i must have something set not quite right, i will have to look thru the manual on the flash and see what olps means, also my flash is in slave mode is that the correct mode for off camera flash,
     
  5. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    Ok, 1st things first. zoom =/= flash power. So the zoom function isn't the amount of power going out from the flash, but rather the concentration/focus of it... which kind of does that, but isn't related to it's power output nor ttl. Here is some food for thought for you.

    Your zoom function controls the spread of your light. If your subject is stationary and you are moving around/zooming with the flash on your camera, it makes since for the flash to match the zoom of the camera to keep it's coverage area roughly the same as what the lens is seeing. BUT if you take your flash off camera, it stops moving with you (unless it's in your hand, which would make it hard to zoom... but this is where a ttl cord would be better for your needs). So if your flash is in a stationary in relation to your subject, and only you are moving, if the flash started zooming with your lens then it would no longer be proportionate to your subject vs what you had set it to. You don't want your flash zooming in and out when it's off camera. That would make me crazy.

    If you need to adjust it from a trigger, it's function 02. But once its set in relation to your subject, it would be rare to need to change it.
     
  6. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    ahhh ok thank you, that makes sence but then again why do they make ttl triggers, i purposely bought this trigger thinking it would do exactly as i sugested, the flash would adjust according to zoom like it does on camera, they make very cheap single pole triggers just to make the flash trigger, so a ttl trigger doesnt really do anything different than a non ttl trigger? again i apploogize for the newb questions but i am still kinda confused as to why ttl works on camera and with a ttl trigger it doesnt, i have a set of yoguno basic triggers with little dip switches for the channel etc, would those have done the same as this x1t0 trigger?
     
  7. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    The ttl function for off camera use will adjust the power of your flash to achieve what the camera thinks is a correct exposure, the same as when it’s on camera. In theory it takes most of the guess work out of the manual settings, but it lacks the precision, control, and repeatability of manual.

    The auto zoom function is not connected to ttl.
     
  8. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    what i am doing is setting the flash on a tripod to the side of my sublect and when i am wide angle to the subject i assumed the ttl would shoot a wide throw of light then when i zoom in to the same subject the ttl mode would adjust the light accordingly, is this not the case? this is wny i purchased the x1t0 for this very reason, to change the throw of light according to my zoom settings, if u have to go in and change them manually i dont see the reasoning behind ttl mode for triggers, i must be missing something haha, i was hoping the flash would adjust like it does on camera in ttl mode i am very confised why this isnt the case, again thank u for explaining things to me as i am a total flash newb but i dont understand why it wont do what i was intending it too,
     
  9. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    ahhh again thank u for expaining, so the auto zoom isnt a throw of light in relation to the zoom level of the lens? i assumed it was, i still think i have something not set right on the flash itself, this trigger is also intended for high speed sync, when i turn that on the trigger and go to say 1/500 my images are underexposed, i dont see the function to turnn it on the flash when i am in the mode the flash works with the trigger, my screen turns red on the flash in the mode it seems to work in but theres no mode for hss when i am in that. found the manual but i am not seeing hss with a trigger,
     
  10. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    Ok ttl doesn’t have anything to do with flash zoom or fov. “Through the Lens” aka ttl is only for adjusting power based on what your camera believes is a correct exposure. Even on camera, if you set it to manual it will still auto zoom. Off camera, auto zoom doesn’t work on purpose. If it started zooming in and out when it was placed on a stand, just because I was using a zoom lens, it would be wonky as hell, sometimes lighting just a persons shoulder instead of the whole body.

    Btw, the x1t also provides high speed sync, letting you go higher shutter speeds than your camera normally goes... and is honestly the only reason I use it over the manual only trigger.
     
  11. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    HHS eats a lot of power, so you might have to adjust your flash power accordingly. And the higher shutter speed you go, the more power it eats. This can be countered by wider aperture or higher ISOs, or using an nd filter instead of hss, or a more powerful light... it all depends on what you’re trying to do with it.
     
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  12. FYI auto-zoom is also normally automatically disabled and forced to maximum wide angle in newer flashes if you drop the wide angle diffusion panel or tilt the flash up, because it assumes that you're now doing wide angle bounce flash rather than frontal key.
     
  13. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    thanx so much for the info, ill keep playing around with it, cant seem to get the hss to work with the trigger, i dont see the option when i am in slave mode, manual wasnt much good either.
     
  14. PakkyT

    PakkyT Mu-43 All-Pro

    Jun 20, 2015
    New England
    My understanding of it, which may have errors of course ;) , is that TTL is simply the camera firing a pre-flash from the flash, evaluating the scene for exposure and then firing the required flash output to properly expose the shot. This literally happens faster than you eye can detect. The zooming of the flash head is to concentrate the light into a smaller area when zooming in so you don't need to use as much energy. While on camera the flash head will auto zoom with the lens in order to help concentrate the light on your subject and will use less energy. But that is simply a helper to the flash system. The TTL system still takes a pre-flash shot to determine exposure. So on the camera, if your lens is at 42mm the flash will zoom in to 42mm and TTL will detect whatever light is needed to expose the scene. If you instead take the flash off the camera and set it to 14mm but keep it the same distance from your subject, TTL again will determine the correct exposure and (at the same distance from your subject) will have to fire the flash harder to get the correct exposure. Both shots in theory should have the same exposure. Just that the on camera flash will use less energy and be ready to to take the next shot much quicker than the off camera shot which will require a bit more recharge time to make up for the more energy used to expose the scene since much of the flash output will be wasted illuminating areas the zoomed lens is not capturing.

    Off camera your flash has no idea what the zoom of your lens is since there is no real-time communication between the flash and camera. Only when you fire the shot will your camera command the flash to output a certain power. In the case of off camera use if you want to use less energy, you will need to manually set the zoom head of the flash to match your lens. You lose the "helper" ability of on camera use.

    Or put very simply, TTL and real-time communication (before the shot) between the flash and camera are two different things.
     
  15. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017

    ok i understand that theory but i believe tthe camera and flash do comuiniacte in real time off camera via the huge ttl trigger,when i make a change on the trigger the flash sees it instantly, what i dont understand is if i zoom in to say 80mm off camera why the flash doesnt see that 80mm and do its test fire at ttl and 80mm and if its correct then it shoots at that, if the trigger is indeed ttl and the flash is ttl then the flash must see basically the sublject i am shooting and if it knows i am at 80mm then throw that light according to 80mm just like on camera, if i am indeed at 80mm the flash should see that and help accordingly, i see that it doesnt work like i thought it would but i dont understand why it cant work like on camera, zoom is zoom whether its on camera or off, the flash would do its test fire,if i placed the flash 2ft from the sublject and stood back 10 ft and zoomed in the flash would do its test fire at ttl and zoom at 80mm and it would prob be to much so the next fire would be less power? thats how i thought it would work, no big deal i will learn how to use the off camera flash the way it works, there is some great info on this site and very knowledgeable people wiling to help
     
  16. Repp

    Repp Mu-43 All-Pro Subscribing Member

    Jan 27, 2011
    Seoul, South Korea
    The reason why the zoom doesn’t change is because its only covering the same field of view as your lens if it’s on the camera. Once its off camera, there is no way for the flash to know where it is in relation to your camera or the subject, so the zoom doesn’t change, only the power coming out of the flash. And if it did zoom in, when off camera, it would be a bad thing.
     
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  17. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    When the flash is mounted on your camera, it generally knows the distance to the subject and angle of view because the camera and flash are married. However, as soon as your flash goes off camera, it has absolutely no idea how close that flash is relative to the subject. You could place the flash 0.5 meters from the subject, firing through a big softbox for very diffuse light, but be shooting with a lens like the Olympus 45 or 75, which means that you're much further from the subject than your light source.

    That is why off-camera flash doesn't care about the focal length you're using, and why it only matters when the flash is mounted in the hot shoe. As soon as you go off-camera, that connection of the distance the flash is from the subject and the angle of view of the lens is broken.
     
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  18. inkista

    inkista Mu-43 Veteran

    464
    Jan 13, 2012
    San Diego, CA
    The X1T transmitter cannot communicate automatic zoom control. You can set it manually (universally for all the slave flashes) with C.Fn-02 on the X1T-O. And you can set it manually by group on an XPro trigger, but the -O version hasn't even been announced yet. But as far as I can tell, it only works with TTL speedlights. The zoom on my TT600s cannot be remotely controlled at all, only on my TT685C.

    This is one of the few ways in which Yongnuo triggers are nicer than Godox's. But, of course, Yongnuo never supported TTL/HSS for MFT, or HSS on their manual-only flashes, so I was more than happy with the tradeoff.
     
  19. You have the X1T-o trigger. If you are not getting HSS, make sure you turn it on - it is just in front of the On/Off slider on the right side of the X1T-o. But, as mentioned HSS uses a LOT of battery trying to make sure you have light during your super fast exposure. I suggest looking into ND filters to keep a large aperture while shooting at normal shutter synch speeds. It will be easier on your flash, and has the great benefit of allowing you to use a different flash (when yours is not with you, or breaks, or whatever). Similar to the advantage of learning how to work without TTL., it allows you more flexibility of gear - which you'll appreciate as you use flash more.
     
  20. genesimmons

    genesimmons Mu-43 Top Veteran

    560
    Feb 12, 2017
    awsome thank u all for schooling me on the differences of on and off camera flash and for the use of hss, i am very new to the whole thing and i am facinated by the work i see with flash and strobes etc, baby steps haha, thank u all again for taking the time to explain things and actually explaining many times as i am stubborn haha
     
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