Defeating pre flash on FZ18

Discussion in 'Digital Photography' started by Guest, Sep 10, 2008.

  1. Guest

    Guest Guest

    I want to use a slave flash but the pre flash prevents this.
    Old Bob
     
    Guest, Sep 10, 2008
    #1
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  2. Guest

    RobertL Guest

    RobertL, Sep 10, 2008
    #2
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  3. On Wed, 10 Sep 2008 11:42:50 -0400, Alan Browne
    <> wrote:

    > wrote:
    >> I want to use a slave flash but the pre flash prevents this.
    >> Old Bob

    >
    >DSLR's and many ZLR's allow setting the flash to manual (no pre-flash).
    >
    >You can also get a Wein device that plugs into the studio flash that
    >skips the pre-flash and fires on the next flash. (you have to disable
    >the slave detector [which is sometimes defeated by the plug-in])
    >

    I had this same problem with my Pentax K10D, it does NOT allow you to
    defeat the preflash, in any setup. So, B&H Photo suggested a Wein
    "Safe Sync" which fits onto the Hot Shoe, and can be cable connected
    to the slave flash. I bought it, plus found a suitable cable locally,
    and no longer have to be annoyed by that stupid preflash.

    Olin McDaniel
    To reply by email, please remove "abcd" from Return address
    -----------------------------------------------------
    "Ignorance is treatable, Stupidity is incurable. Sometimes
    the difference is hardly distinguishable, however."
     
    Olin K. McDaniel, Sep 10, 2008
    #3
  4. Alan Browne wrote:

    > wrote:
    >> I want to use a slave flash but the pre flash prevents this.
    >> Old Bob

    >
    > DSLR's and many ZLR's allow setting the flash to manual (no pre-flash).
    >
    > You can also get a Wein device that plugs into the studio flash that
    > skips the pre-flash and fires on the next flash. (you have to disable
    > the slave detector [which is sometimes defeated by the plug-in])


    I've looked at the Digital Peanut (I have three regular Peanuts). Don't
    some cameras do two red-eye-reduction preflashes? If I'm right on that, I
    don't see how to set the DP to ignore more than one preflash, since like
    its little brother it's housed in a glob of acryllic with nothing sticking
    out but the connector. (I'm speaking of the plastic-dome DP, natch.)


    --
    Blinky
    Killing all posts from Google Groups
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    Blinky the Shark, Sep 10, 2008
    #4
  5. On Wed, 10 Sep 2008 16:27:33 -0400, Alan Browne
    <> wrote:

    >Olin K. McDaniel wrote:
    >
    >> I had this same problem with my Pentax K10D, it does NOT allow you to
    >> defeat the preflash, in any setup.

    >
    >It surprises me that Pentax would be that dumb... and something that
    >could easily be fixed with a firmware update too.
    >


    I agree, and I felt that way also. But they do not show ANY interest
    in such a suggestion. I believe, but not sure, they did fix this
    oversight in the next model, the K20D.

    >> So, B&H Photo suggested a Wein
    >> "Safe Sync" which fits onto the Hot Shoe, and can be cable connected
    >> to the slave flash. I bought it, plus found a suitable cable locally,
    >> and no longer have to be annoyed by that stupid preflash.

    >


    >That's not what I was referring too. The whole point of slaves is to
    >get away from a sync cable.
    >


    Well, that was also part of my solution, but chose not to get too
    verbose in the earlier reply. I do have an ancient slave flash that I
    built the optical trigger for, and the preflash was screwing it up all
    the time. My solution for that was to buy a used Hot Shoe mounted
    flash to mount on top of the "Safe Sync" and let it fire - this then
    triggers the remotely located slave flash. That used flash cost me
    all of $13.

    >I mean a flash sensor that plugs into the studio light sync plug. When
    >it sees a flash, it ignores it and then trips on the next one. (I
    >suppose it resets fast if it only sees one flash so that it can't get
    >out of phases with what's going on...).
    >

    Olin McDaniel
    To reply by email, please remove "abcd" from Return address
    -----------------------------------------------------
    "Ignorance is treatable, Stupidity is incurable. Sometimes
    the difference is hardly distinguishable, however."
     
    Olin K. McDaniel, Sep 10, 2008
    #5
  6. Alan Browne wrote:

    > Blinky the Shark wrote:
    >> Alan Browne wrote:
    >>
    >>> wrote:
    >>>> I want to use a slave flash but the pre flash prevents this.
    >>>> Old Bob
    >>> DSLR's and many ZLR's allow setting the flash to manual (no pre-flash).
    >>>
    >>> You can also get a Wein device that plugs into the studio flash that
    >>> skips the pre-flash and fires on the next flash. (you have to disable
    >>> the slave detector [which is sometimes defeated by the plug-in])

    >>
    >> I've looked at the Digital Peanut (I have three regular Peanuts). Don't
    >> some cameras do two red-eye-reduction preflashes? If I'm right on that, I
    >> don't see how to set the DP to ignore more than one preflash, since like
    >> its little brother it's housed in a glob of acryllic with nothing sticking
    >> out but the connector. (I'm speaking of the plastic-dome DP, natch.)

    >
    > I really don't know the details. I may have read that you can set them
    > for a specific count. That might be my imagination. Or a fish.
    >
    > I don't have this issue with Minolta as I can set built in or attachment
    > flashes to manual which kills the pre-flash.
    >
    > As to flash for red-eye, that's a real dumb idea - And Konica-Minolta
    > does just that on the Maxxum 7D. What crap! Makes
    > deer-in-the-headlight shots or people blinking and turning away...
    > dumb-de-dumb-dumb. Is it Nikon that uses a white light for this?


    My D60 does. It's also the low-light AF assist illuminator.

    BUT...from my SB-600 speedlight manual: "To prevent the center of your
    subject's eyes from appearing red in color pictures, the SB-600 fires
    three flashes at reduced output just before the picture is taken."

    > That's the way to go.
    >
    > Having blabbered all that, I don't use built in flash (or hardly ever)
    > except in the studio to trip the strobes ... with a bit of cardboard to
    > deflect the light away from the subject.


    Similar here.

    --
    Blinky
    Killing all posts from Google Groups
    The Usenet Improvement Project: http://improve-usenet.org
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    Blinky the Shark, Sep 10, 2008
    #6
  7. Guest

    Bob Williams Guest

    wrote:
    > I want to use a slave flash but the pre flash prevents this.
    > Old Bob
    >
    >

    Here's something you might try that should work ....and its free.
    The preflash is very much weaker than the main flash.
    So you could tape 1,2,.....n little pieces of typing paper over the
    slave sensor until the preflash does not set off the slave but the main
    flash does. If it takes more than 4-5 thicknesses of paper to defeat the
    slave, you might try darkening them with a black "Marks-a-Lot".
    You will find the sweet spot after a few trials.
    Bob Williams
     
    Bob Williams, Sep 11, 2008
    #7
  8. Guest

    Guest Guest

    Thanks Robert, I have ordered to slave you reccomended
    Old Bob
     
    Guest, Sep 14, 2008
    #8
  9. Guest

    Bob Williams Guest

    Alan Browne wrote:
    > Bob Williams wrote:
    >> wrote:
    >>> I want to use a slave flash but the pre flash prevents this.
    >>> Old Bob
    >>>

    >> Here's something you might try that should work ....and its free.
    >> The preflash is very much weaker than the main flash.
    >> So you could tape 1,2,.....n little pieces of typing paper over the
    >> slave sensor until the preflash does not set off the slave but the
    >> main flash does. If it takes more than 4-5 thicknesses of paper to
    >> defeat the slave, you might try darkening them with a black
    >> "Marks-a-Lot".
    >> You will find the sweet spot after a few trials.
    >> Bob Williams

    >
    > I think that might be a bit hairy-fairy to find... and the slave sensors
    > are very sensitive.
    >
    > When I set off my slaves in the studio I usually set the source flash to
    > 1/32 (whether the built in flash or the attachment). When the
    > attachment, then I point it away; when the built in I deflect it with a
    > business card in front of the flash.
    >
    > So, not much power and double reflected off of odd surfaces at that...



    It is not really all that important how sensitive the slave sensor is.
    What is important is the DIFFERENCE in intensity between the preflash
    and the main flash.
    There will always be a sufficiently opaque material to completely
    disable the slave sensor. For instance, consider a piece of black
    electrical tape with a pinhole aperture in its center covering the
    sensor. There will always be some aperture size that will ignore the
    preflash but fire on the main flash. It shouldn't be hard to find the
    sweet spot, and the price is sure right.
    Bob Williams
     
    Bob Williams, Sep 15, 2008
    #9
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