Canon 5D flash sync question.

Discussion in 'Canon' started by Eric Miller, Jul 9, 2008.

  1. Eric Miller

    Eric Miller Guest

    Since this subject is related to flash sync, I thought I'd ask it here.
    I have been taking some product shots for a new website I will be
    launching in a few weeks (it's actually up and running, but not much is
    there). While taking my product shots, I noticed some shading of what
    should have been an even background (different colored backdrops). I
    decided to lower the shutter speed, because it looked like a sync problem.

    Here are two photos that show the effect:

    http://www.dyesscreek.com/hidden_pages/sync.html

    On the left is a 1/200 exposure. On the right, 1/160. After some brief
    research, I found that the 5D manual states that the sync for studio
    strobes may be as low as 1/125 so I was relieved that it didn't
    indicated any problem. My question is why the difference between the
    studio strobes and a hotshoe flash? The obvious answer would seem to be
    the flash duration, but on second thought, that can't be it, can it? I
    am using Alien Bees B800s which supposedly have a flash duration that is
    1/3200 or so and even at half that, I didn't think that slow enough to
    cause a sync problem. At full power many hot shoe flashes have a flash
    duration in excess of 1/1000. What gives?

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 9, 2008
    #1
    1. Advertisements

  2. Eric Miller

    jimkramer Guest

    Not about flash duration, but all about signal propagation. It's all about
    timing and how long the signal to "Fire the Flash" takes to get to the
    flash. You can try rear curtain sync and see if that makes the problem go
    away or makes it worse. You also mention using a wireless sync system to
    shoot, that just adds to the likelihood of a delay.

    On a side note make sure you look at the website on someone else's computer
    or force the font to be one that supports the last 2 characters in your
    sauce's name. I just get little squares.

    -Jim
     
    jimkramer, Jul 9, 2008
    #2
    1. Advertisements

  3. Eric Miller

    Colin_D Guest

    How can that be?? The images are images - pictures, no text as such.

    Colin D.
     
    Colin_D, Jul 9, 2008
    #3
  4. Eric Miller

    Colin_D Guest

    It's a sync problem. The shutter is opening before the flash gets
    going. It appears the second curtain is starting to close before the
    flash has started, and using a slower shutter speed has delayed the
    second curtain enough to catch the flash.

    This effecr may be your cheapie radio link, or it may be characteristic
    of Alien Bees. You could check the specs for any trigger delay in the
    units, and this may be a reason for recommended slow speeds, even though
    the flash itself may go off at 1/000 or shorter.

    On the image of the bottle, both lamps are clearly reflected in the neck
    of the bottle. I would try to eliminate that.
    Colin D.
     
    Colin_D, Jul 9, 2008
    #4
  5. Eric Miller

    That Rich Guest

    Uh...

    *el* for bechemel.
    or
    *ce* for demi-glace
    or
    *se* for bordelaise
    or
    *ur* for chasseur
    or
    *ra* for madeira

    Just trying to help.

    Hope all is well in LA.

    I reamain,

    lover of French sauces,

    RP©
    -
    If it doesn't have garlic in it, it's dessert
     
    That Rich, Jul 9, 2008
    #5
  6. Eric Miller

    Bruce Guest


    I get little squares in Internet Explorer, but a white question mark
    within a black diamond in Mozilla Firefox.

    Something definitely isn't right.

    I like the sound of the sauce, though!
     
    Bruce, Jul 9, 2008
    #6
  7. Eric Miller

    jimkramer Guest


    I thought that you were a Mexican cuisine aficionado? And where does garlic
    flavored ice cream fall? :)

    The only real problems so far (aside from the heat & humidity) are the
    roads. I came from NC (The good roads state, no kidding) and in MS they
    have this "Yazoo Clay" that makes the roads turn into roller coaster rides.
    Driving with a beverage is difficult and driving with a hot beverage is down
    right dangerous.

    -Jim
     
    jimkramer, Jul 9, 2008
    #7
  8. Eric Miller

    That Rich Guest


    Aficionado, hell.
    Just like to eat!

    Hmmmmm... garlic ice cream. One o' dem impossible to classify objects.
    Never tried it myself.

    RP©
     
    That Rich, Jul 9, 2008
    #8
  9. Eric Miller

    Eric Miller Guest


    Yes, I have been having trouble with that. My style sheets are fighting me
    at the moment. I am using Arial, which should support those characters -
    "í®". It will be a few weeks before I can sell through the website so I
    hope to work it out before then.

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 9, 2008
    #9
  10. Eric Miller

    jimkramer Guest

    Near the bottom is the website address that he was taking the pictures for.
    That site is where the font issue pops up.
    -Jim
     
    jimkramer, Jul 9, 2008
    #10
  11. Eric Miller

    Eric Miller Guest

    It's a sync problem. The shutter is opening before the flash gets going.
    The recommendation for slow speeds with studio flash comes from Canon,
    though it may related to some triggering issue with the flash units. In any
    event, I've never noticed the problem with hotshoe units triggered by the
    same cheapie radio link (which seems to work flawlessly).
    I initially had trouble with glossy labels that were reflecting the flash
    units and used a light tent before just printing my own on plain paper for
    photography purposes. The neck reflections are a little more troublesome
    because of the curve at the bottom. I can remove the higher reflections by
    raising the lights but the lower ones will still be there. I'll likely end
    up shooting with the lights in multiple positions and then stitching
    together a bottle with no reflections. Here is the current image as it
    appears on the hot sauce website:

    http://www.colibrihotsauce.com/

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 9, 2008
    #11
  12. Eric Miller

    Alan Browne Guest

    It's the trigger time from front-curtain open to the time the flash
    actually firing.

    I think the caption you put: "cheap wireless sync" is the problem.
    Please DO name the brand.

    The 'bees are not the problem.

    Get PocketWizards. I've used them at 1/300 with no problem at all and I
    would bet they would work well at 1/500 as well.

    You can also get a pocketwizard compatible module for Sekonic meters (my
    meter has the capability, but I haven't bought the module.

    By the way, "Hummingbird" does not seem like a great name for a hot
    sauce. Reddy-woodpecker would do it.
     
    Alan Browne, Jul 9, 2008
    #12
  13. Eric Miller

    Eric Miller Guest

    Notice the red throat? Anyway, most people don't know or care what
    "colibrí" means. I have given some thought to using a picture of a Red-
    tailed Hawk, but I think that is already taken.

    As to the less than clear name, I plead "tabasco" as my defense.

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 9, 2008
    #13
  14. Eric Miller

    jimkramer Guest

    The name doesn't need to be clear, just memorable... success!
    http://dictionary.reference.com/browse/colibrí

    :)

    -Jim
     
    jimkramer, Jul 10, 2008
    #14
  15. Eric Miller

    Annika1980 Guest

    Ready Woodpecker is the name of Rita's dildo.
     
    Annika1980, Jul 10, 2008
    #15
  16. Eric Miller

    Eric Miller Guest

    If I knew the brand name, I'd tell ya. The only english on the box is:

    Yinhe Technology Development Corp.

    Maybe that is the brand, but I doubt it due to all the much more
    prominent characters from some other language.
    Maybe, but I have added a shot taken today with a pc-sync cord. Same link:

    http://www.dyesscreek.com/hidden_pages/sync.html

    Similar, but not quite as pronounced result. BTW, what camera and
    strobes were you using your pocketwizzards with a 1/300?
    I used to have a Gossen Ultra Pro meter but sold it after I switched to
    digital.

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 10, 2008
    #16
  17. Eric Miller

    Eric Miller Guest

    You'd probably like the flavor much better!

    Eric Miller
    www.dyesscreek.com
     
    Eric Miller, Jul 10, 2008
    #17
  18. Eric Miller

    Alan Browne Guest

    She needs one. No sane human would go where that dildo goes...
     
    Alan Browne, Jul 12, 2008
    #18
  19. Eric Miller

    Alan Browne Guest

    Strange. The 5D should not have this problem. It's as if there was
    some parasitic capacitance somewhere that is delaying the strobe firing.
    Althouh I'm cofident in your bees, maybe you better call them up.
    Maxxum 9 film camera (syncs to 1/300).

    Strobes are a French low end brand called Multiblitz that I bought from
    a pro who was upgrading to a pak system. I've triggered them with sync
    cord, slave and PocketWizards to 1/300 with no problem. (For that
    matter to 1/320 on the Maxxum 9 w/o visible effect. At 1/350 they start
    to shadow on one edge. [room temp]).

    I do hope the new Sony 24.5 Mpix camera will sport a 1/300 sync as well
    (or at least 1/250).

    I've always wanted to get three bees and many accessories (A couple
    800's and a 400 or 1 ea of 1600, 800 and 400). But always other
    priorites. (I did a total of three studio projects in 2007 and 0 in
    2008... so hard to justify. My SO has also turned my studio into
    something called a "living room").
    tsk, tsk!

    Cheers,
    Alan.
     
    Alan Browne, Jul 12, 2008
    #19
  20. Eric Miller

    Alan Browne Guest

    I remain a lover of Saucy French women.
     
    Alan Browne, Jul 12, 2008
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.