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Optical Triggers - Where?

Discussion in 'General flash photography, lighting, and technique' started by phecksel, Jul 23, 2007.

  1. I've seen a couple of references to "cheap" optical triggers. Where do I purchase such a thing, and will they work with the old vivitar flash I found in my dads bag of camera stuff?

    Thank you,
     
  2. Funny, I just got done ordering these after following this thread for quite a while... hope these are what you're looking for, and yes, there is info on what flashes they seem to work well with, you just have to dig for it: http://www.flickr.com/groups/strobist/discuss/72157600136709187/

    I just ordered mine direct from the dealer, Gadget Infinity.
     
  3. jcovert

    jcovert Guest

    phecksel, I ordered mine from MPEX (the link is at the top of the strobist page) for $15 bucks. works w/ vivitar..

    however...In my setup, if I just use the ONE Vivitar strobe w/optical trigger - the flash gets fired, but it (for some reason) does not sync with the picture correctly, so the pics looked like no flash even fired.

    Basically, doesn't work as expected.

    ...but if I use my SB800 flash AND the Vivitar w/optical trigger (2 flash setup) - then both flashes fire in sync with the camera, and both flashes register as expected in the picture..

    So it seems somehow that my SB800 is what is making the optical trigger work correctly. Why? I have no idea.
     
  4. What are you using to trigger the slave flash?

    Ronnie
     
  5. jcovert

    jcovert Guest

    In all cases I'm using the D70 as a trigger (Commander Mode, manual). But why the SB800 helps the vivitar/optical trigger out, I'm not sure.
     

  6. Hmmm, I don't understand either. Adding an SB800 shouldn't change the flash timing. Unless your using the SB800 in manual in CLS mode and not SU-4 mode. In that mode there are preflashes which may change timing. Does the slave have an "ignore preflashes" mode which is perhaps on when it shouldn't be ?

    Ronnie
     
  7. jcovert

    jcovert Guest

    Not sure what SU-4 mode is, and I am using the SB800 in manual mode (ok I see it now...mine is set to "Remote" not "SU-4" in the wireless options of the SB800)

    The optical slave has NO settings available to it. Just looks like a hotshoe with a white area on front for sensing light.

    (sort of off topic but, I find it interesting that I can cup my hand over the D70 pre-flash, with the SB800 behind a curtain, and it still all triggers fine. The SB800 must be very sensitive.)

    Again, I don't get it Ronnie. I actually look at the flash when I click the shutter, and I see it flash, but the light is not in the picture.:confused: 
     
  8. Hmm. With the SB800 in "remote" mode there will be preflashes from the D70 even in manual mode since it needs to tell the Sb800 what power is needed. It may be that the delay in firing the optical slave is enough that these preflashes make it go off at the right time. When the D70 is in M mode there are no preflashes so the optical slave is late.

    Try the D70 in manual, the SB800 in SU-4 and see if you see the vivitar flash in the picture then. I'll bet it's late. Another way to confirm this would be to try a slower shutter speed (say 1/15th or slower) to see if the vivitar flash registers in the image then.

    Ronnie
     
  9. jcovert

    jcovert Guest

    Will try it Ronnie, thanks for the help!
     
  10. WayneF

    WayneF

    Apr 3, 2006
    Texas
    You can use the Vivitar flash and external trigger with the D70, but NOT if in Commander mode. That equipment is not designed to understand the Nikon CLS system. The SB-800 Remote mode does, but you added a third party flash.

    Nikon Commander mode means that when you press the shutter button, the D70 internal flash fires special preflashes which tells the SB-800 or SB-600 in Remote mode to fire a test flash, and the D70 light meter reads that test flash intensity on the subject, and sends another preflash to set level of the remotes, and to fire them. Then the shutter opens ready for that final firing. The SB-800 understands all of that in Remote mode.

    But... There is considerable delay in all of that, and the third party trigger/flash does not understand any of this, and it will fire with the first preflash, and so it is done and dark by the time the shutter opens (no contribution to picture exposure). Digital flash is very different than film flash, and all automatic digital flash uses preflash, and must be set to manual mode to prevent preflash in order to be compatible with external equipment which does not understand digital preflash.

    What you should do is this:

    Program the D70 flash menu to be in Manual flash mode
    (not Commander, and not TTL, not if using 3rd party flash gear).

    Set the D70 exposure mode to Manual, and set aperture manually which means you either meter a test shot with a flash meter, or you guess at f/stop value until you get the correct exposure.

    Set the SB-800 to SU-4 mode and manual mode, which means it will will trigger in sync with any external flash (which is also what the third party trigger does). SU-4 mode means it works like the external trigger unit you bought, built in - but manual.

    Then either use the internal flash at low power (like 1/16 power) to trigger the other lights, or use a PC cord to one of them so that it triggers the other.

    If the D70 flash mode menu is set to Manual Flash (not Commander, not TTL), it will work as you expect with the third party equipment.
    But if not manual flash menu mode, then it will do preflash, some degree of it in iTTL mode, and much more in Commander mode, and unfortunately, the third party equipment does not speak Nikon digital preflash.

    FWIW: There are a few such optical triggers that have a switch for film mode or digital mode, which can work with digital preflash - for example point & shoot cameras, and even the D70 in iTTL mode, but these still cannot work with the Nikon Commander mode.

    If you instead want to use Nikon iTTL or Commander mode, then you need new model Nikon flashes that understand it, like SB-800 or SB-600. Even older Nikon flashes that do TTL do not do iTTL, and so still do NOT work with the D70 digital flash modes.
     
  11. jcovert

    jcovert Guest

    Thank you very much Wayne! I will try it out.

    Question though...right now, with my D70 in Commander Mode>Manual, and my SB800 set to Remote and also manual power (not set to TTL, TTL-BL or AA but Manual) - the Vivitar is working as expected in this scenario..

    1.) Would there be 2 pre-flashes or only 1? since the SB800 is on manual?
    2.) Is the fact that the Vivitar works under these conditions just entirely a lucky fluke having to do with the timing?

    Thanks again for the great insight Wayne. I look forward to experimenting with your method.

    Cheers!
     
  12. WayneF

    WayneF

    Apr 3, 2006
    Texas
    Don't know and am hesitant to guess about the exact nature of the preflashes. What you describe seems a wild combination, but not sure it matters how many, as one preflash is enough to trigger the manual flash and totally ruin the deal.

    If the Vivitar is working, then I assume you must also have the camera exposure mode in manual M position (where you set the aperture yourself). Manual exposure mode should disable preflash. However if you also specify Commander mode, then it seems like an invalid combination, and I dont know what the internal meter actually does. If used to trigger the external flash, the internal flash must fire, and I fear Commander mode may feel the need to try to set the power level of the remote flash to match the aperture you set, which only works via preflash. Guessing, I dont know, but I doubt that is what you intended. But Manual camera exposure mode is said to disable preflash, so probably it does, and Commander mode is probably ignored too (except the internal flash must fire, and it is not in manual mode, so what does it do?) Since you said the Vivitar worked, then that must be the case, Commander must be ignored. The Vivitar cannot work with Commander mode.

    Three things to set: internal flash mode, camera exposure mode, and external flash units, all in manual mode. This eliminates preflash and lets the Vivitar trigger work without wondering about it. Or if you instead set D70 Commander mode, then all the flash units should be SB-800 or SB-600 units, and all in Remote mode for CLS. and you would not likely use Manual exposure mode then.

    If wanting manual mode, then you might as well use SB-800 SU-4 mode instead of Remote mode (and certainly so with third party extra lights that dont speak CLS). SU-4 mode is a fine remote optical trigger, but it is not CLS capable then.

    I have two SB-800, and I mostly use them in manual SU-4 mode with other studio lights (which are also non-Nikon, non-CLS - like the Vivitar and its optical trigger in that way). They all work together great that way, remotely optically triggered (in SU-4 manual mode). A handheld flash meter makes it all be easy, and lets each lights level be manually set to exactly what you want (CLS can never meter the lights individually). Camera exposure mode and internal flash mode also set to manual ... Then the internal flash could trigger the external lights, but I use a PC cord to any one of the lights, so I keep the internal flash door shut.

    Or I also often put one SB-800 in the D70S hot shoe (alone) and set iTTL mode in the camera, and point it at the ceiling in CLS aperture mode (about f5 typically) and it works great then while walking around the room (one light).
     
  13. Manual exposure mode does NOT disable the preflashes. Preflashes will always be present if the built in flash is in commander mode as it has to tell the remote flashes what to do even if you are using "manual" commander mode. So commander mode and manual exposure mode ARE compatible. In iTTL the camera will set the flash to match the aperture, in "manual" your on your own. :) 

    What I suspect is happening is that the optical slave you have is one designed for use with digital cameras so it has a delay to compensate for the preflashes. That's why it works in commander mode and not otherwise.

    Have you tried using a much slower shutter speed yet to see if the flash registers then?

    Ronnie
     
  14. jcovert

    jcovert Guest

    o.k.! I figured out what's happening here (which I would not have done without your info Wayne), but first let me say this thread has gone a little above my head, so forgive me if explain this in my highly unscientific manner:wink:

    - The pre-flashes from the D70 are so extremely weak that in my setup, the pre-flashes do not set off the optical trigger (most of the time.) I had to either 1.) put the optical trigger/Vivitar close in front of the D70, or 2.) cup my hand and direct the pre-flash light into the umbrella (then setup 1 ft. to my right) in order to get the pre-flash to set off the optical trigger.

    And of course then, even though it fired, it didn't contribute to the exposure because it was too early. (So there was no shutterspeed at which it would register)

    - Setting my D70's Flash settings to Manual Mode (not Commander) at 1/16 power IS enough power to set off the optical trigger, and then the Vivitar contributed to the exposure! (Cool, thanks Wayne :cool:  )

    What's more, I could cup my hand on the D70 flash and eliminate it from the scene, and it still triggered the Vivitar as expected!

    - All this put together explains why my previous setup worked. When I'm using the SB800, the D70 sends it pre-flashes but those don't trigger the Vivitar. Only when the SB800 actually fires is there enough light to trigger the Vivitar.

    Anyway, thanks very much Wayne and Ronnie for your help. It's great to be able to use the optical trigger/Vivitar now by itself!

    (p.s. I can even set my shutterspeed to 1/500, and the optical trigger still fires and get's it's light into the scene with no problem. Some basic math shows how fast light really is! If my math is right, the flash would have to be over 1800 ft. away at 1/500 for it to miss the scene!)
     
  15. WayneF

    WayneF

    Apr 3, 2006
    Texas
    Yeah, the internal flash is a very weak unit anyway, and 1/16 of that weak power is four more stops down, which normally will not affect the picture when also blasted with much larger lights. Possibly an insignificant fill up close, but probably never visible at all. Yet it does seem to trigger the other triggers well. But I still prefer a simple PC sync cord to the nearest light actually used. This is the failing of the SB-600, it has neither SU-4 mode nor a PC cord connector, which the SB-800 has.

    Note the D70 has two Manual flash modes. It has a flash mode menu for Manual, iTTL, or Commander, and I have been referring to that Manual choice, to take it out of Commander mode. And its Commander mode also has a submenu for Manual, AA, or iTTL, and I did not mean that Manual Commander choice. Flash can become a very large subject. :)  I think there is much to be said for manual mode with a handheld flash meter - easy and obvious.

    And if testing how preflash affects manual flash units, note the SB-800 SU-4 mode is not your ordinary optical trigger. It does that exceptionally well, but its SU-4 mode will trigger "in sync" with the shutter regardless if the D70 internal flash is in any flash mode, Manual, iTTL, or Commander. Not saying SU-4 understands Commander, it is not equivalent to Remote, but I think it simply follows each and every flash it sees, a little like repeat mode. Not saying that is useful, we could specify smarter choices. And not saying the pictures are the same, the light meter can get involved too regarding the overall scene, but simple tests show it triggers at the right time, that is, again with the last flash when shutter is open. The main point is that third party manual lights will not do that - preflash eliminates their contribution for being too early.

    Remote mode needs more information, and will not trigger except in Commander mode.

    Anyway, my opinion is if using Commander mode, then use Commander mode. And if using Manual mode, then use Manual mode. And... any third party optical triggers typically can only use manual mode.
     
  16. jcovert

    jcovert Guest

    Thanks very much for your explanations Wayne. It's helped me immensly and I'm sure others will be helped by your well-detailed explanations as well! Thanks man.
     
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