White Balance filter

Discussion in 'Digital SLR' started by Slack, Jun 16, 2005.

  1. Slack

    Slack Guest

    Slack, Jun 16, 2005
    #1
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  2. The ExpoDisc has been discussed in this forum before, and the
    concensus seem to be that:
    1) it is not very useful (i.e. no substitute for a grey card); and
    2) a Pringle's lid do the same thing and cost less.

    Btw - the explanation on the B&H page looks bogus to me.
    Passing 18 % of diffused ambient light through the ExpoDisc
    is not the same thing as 18 % grey reflected from a grey card.
     
    Gisle Hannemyr, Jun 16, 2005
    #2
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  3. Slack

    Paul H. Guest

    http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=358074&is=REG

    Seems like it has limited utility, IMHO. From the description:

    " It is a neutral diffusion filter that gathers ambient light from 180° and
    passively transmits 18% of it through to your camera's light meter. The
    resulting "gray frame" accurately represents the average colorcast of the
    light in which the photograph is taken. From this gray frame, you then can
    set a custom white balance that results in accurate color in most lighting
    conditions. Your camera effectively compensates for and neutralizes the
    colorcast it sees through the ExpoDisc 'gray frame.' "

    It sounds as if you could accomplish the same thing by slipping a 5-cent
    white styrofoam coffee cup over the front of your lens, then performing a
    custom white balance. Furthermore, since using a gray or white card is such
    a triviality (I keep white, gray, and warming-gray cards in the front pocket
    of my bag), ExpoDisc seems more like a high-price solution in search of a
    problem: I mean, you have to take the thing out, screw it on your lens, do
    the white balance procedure, take it off, put it way, then get on with your
    picture-taking. I don't see how that's easier, faster, or better than using
    a white or gray card, unless you get some odd thrill from the act of
    screwing filters on and off.

    And lastly, I can think of other, more useful gizmos to spend $120 on.
     
    Paul H., Jun 16, 2005
    #3
  4. Slack

    Rudy Benner Guest

    I was particularly interested in this for an underwater application, then
    someone mentioned the lid from a Pringles container. That would probably be
    a lot cheaper. Perhaps not perfect, but it would get me into the ballpark.
    Photoshop could take care of the rest.

    I tried a grey card laminated, the lamination was not perfect and it got
    soaked. Tried a white slate, that worked fairly well. Some folks just use
    the palm of their hand for a reference. Its a bitch, trying to hold the
    camera in its housing with a strobe attached, hold a grey card in front,
    properly positioned for ambient, using that third hand all photographers
    have to press the appropriate button on the housing to set the white
    balance, all the while maintaining neutral buoyancy. ARRRRRRHHHH !! Then
    when things are all set, we find that the subject has departed.

    More suggestions please.
     
    Rudy Benner, Jun 16, 2005
    #4
  5. Slack

    Alan Browne Guest

    Set the camera "whitebalance" according to the light source (in Kelvin
    if possible), and you will get the color consistency claimed by this
    product wihtout having another seldom used widget cluttering up your
    camera bag.

    Then spend the $120 on something useful like CF cards or part of a new lens.

    Cheers,
    Alan.
     
    Alan Browne, Jun 16, 2005
    #5
  6. I did a lot of experimentation with different materials and I found the best
    to be a piece of white acrylic fluorescent light cover (textured pebble
    finish). I mounted a piece in a step-up ring for the various size lenses I
    use. It works great and is very fast and easy to use. I leave it of the
    front of the lens as a protector/cap as well.



    Rita
     
    Rita Ä Berkowitz, Jun 16, 2005
    #6
  7. Slack

    Rudy Benner Guest

    Thanks Rita.
     
    Rudy Benner, Jun 17, 2005
    #7
  8. Slack

    DoN. Nichols Guest

    However, it strikes me that this would have the same problem for
    the requested application as the purchased white-balance filter. How do
    you get it on and off the camera in an underwater housing? You can't
    take the photos with the white balance filter in place. You've got to
    go to the surface to open the housing and remove the filter, and the
    light might have changed by the time you get back to the bottom.

    And for a pebbled surface, mounting it outside the housing would
    have somewhat unpredictable effects, depending on how the index of
    refraction of the plastic compares to that of water. It might behave
    just like a flat piece of the same material under water.

    And if you're using flash underwater, even a 18% gray card
    magically waterproofed might not work unless you have a way of holding
    it at the same distance from the camera as the subject, as you will be
    getting a varying mix of artificial light and light filtered through the
    water.

    You might try a matte gray paint on some aluminum sheet (not
    foil) on a rod mounted below or beside the camera housing.

    Good Luck,
    DoN.
     
    DoN. Nichols, Jun 17, 2005
    #8
  9. Oops, sorry, I missed the UW part of the equation. I was just commenting on
    a direct cheap homebrew replacement for the Expodisc.
    I agree. I think another factor is, depending on optical purity of the
    water and the lens combination, he will have to find an average distance he
    will be shooting at and set his white balance for that. If he stays in the
    same general area and keeps his distance about the same I don't think it is
    going to be a major issue.
    I was thinking the same or even a piece of gray scrap Body Glove material,
    as it's water proof and not very shiny or reflective.

    All just speculation, of course.




    Rita
     
    Rita Ä Berkowitz, Jun 17, 2005
    #9
  10. Slack

    C Wright Guest

    Since this discussion (like most discussions) has changed course a bit with
    people talking about the methods that they use for white balance I'll add my
    2 cents! Here is what I use:
    http://www.rawworkflow.com/products/whibal/index.html
    The color / white balance card set contains four different color cards - a
    dark grey, a white and a black for color balancing and a light grey card for
    use in white balancing. They are made out of plastic so they are water
    proof and the color goes all the way through the plastic so that scratches
    do not affect the color quality. While not a particularly inexpensive
    solution, considering how long the cards will probably last they may be
    cheap in the long run. Fyi - I have no connection to Michael Tapes or his
    products.
    Chuck
     
    C Wright, Jun 17, 2005
    #10
  11. Slack

    RSD99 Guest

    A Kodak 18% Gray Card is cheaper ... and better.
    [Catalog number 152 7795, Publication number R-27]

    A Kodak Q-13 Gray Scale and Color Patch set is cheaper ... and even better
    than the 18% gray card.

    A Macbeth Color Checker is better yet!
     
    RSD99, Jun 18, 2005
    #11
  12. Slack

    DHB Guest

    Maybe I am missing something because I am not, nor ever will
    be a professional photographer but I do have 25+ years of experience
    with 35mm SLR's & 4+ years with Digital cameras.

    As a retired E.T., I have learned to maintain the "K.I.S.S."
    principle whenever possible. Less than a year ago, I read an article
    in a photographic magazine published as a mailed-in tip for setting
    custom white balance using an extremely inexpensive (almost free)
    common household device. The idea was so simple that it seemed too
    good to be true, so the only reasonable thing to do was to try it
    against more conventional methods & see if it worked & if, so how
    well? It did work & it's now my primary method of setting a custom
    WB on both my DSLR & P&S cameras that have a custom WB feature.

    The device is a "white coffee filter" that I slip over the
    lens & is held in place with a rubber band. Works great indoors where
    a gray card may not offer enough light to get a correct WB setting. A
    white piece of copy paper may work also but there is no guarantee that
    it's reflection will be color spectrum neutral & it, like a gray card,
    needs to be propped-up & photographed. This method & device is much
    simpler, almost free, faster & works great 95+ % of the time if you
    get the exposure correct.

    So now each of my camera bags has about 10 "white coffee
    filters" & 3 rubber bands inside of zip-lock baggies to keep them
    clean. The filters can be used a few times or just once & tossed. If
    your outside in direct sunlight overexposure can be a problem but then
    I rarely find myself in need of doing a custom WB in direct sunlight
    unless it's very early morning or late evening light, in this case
    it's usually not too strong to cause overexposure problems.

    It sound silly, but considering the cost, (free if you already
    have them for your coffee machine) I think it's worth giving it a try
    BEFORE telling me about all the reasons why it should or might not
    work well. Also I considered that these "white coffee filters" might
    also not be 100% neutral in the light that they allow though & there
    may also be minor variations depending on the brand & even the lot
    number. After all they are designed to filter coffee not diffuse
    light evenly across the visible spectrum, however they work just fine
    for me & if ever I forget them or run out in the field, they can be
    found & purchased in thousands more stores than an 18% gray card can!

    Maybe my standards are simply lower than other's but when I
    find something that works for me & is very cost effective, I stick
    with it & offer it for others to evaluate in the hopes that it will
    work for them as well.

    Respectfully, DHB


    ..
    "To announce that there must be no criticism of the President,
    or that we are to stand by the President, right or wrong,
    is not only unpatriotic and servile, but is morally treasonable
    to the American public."--Theodore Roosevelt, May 7, 1918
     
    DHB, Jun 18, 2005
    #12
  13. Slack

    Rudy Benner Guest


    Now all I need to do is figure out a way of using it underwater......
     
    Rudy Benner, Jun 18, 2005
    #13
  14. Slack

    Colin D Guest

    *Idea* - if I use a filter after the coffee is brewed, I can take sepia
    colored pictures {:)

    Colin
     
    Colin D, Jun 18, 2005
    #14
  15. Slack

    JPS Guest

    In message <[email protected]>,
    Uh, no ... That's how you get bluish pictures. You get a 180 degree
    shift in hue from the object used for white balance.
    --
     
    JPS, Jun 18, 2005
    #15
  16. Slack

    Slack Guest

    It did work & it's now my primary method of setting a custom

    Awesome... thanks, MacGyver! I love stuff like this.

    Plus, it gives me a good excuse for *not* quiting coffee :) :)
     
    Slack, Jun 18, 2005
    #16
  17. DHB you say this quite negatively: I for example am only a professional by
    definition because it's my job, and your experience is as long as the time I
    have been drawing breath! There are a lot of excellent unpaid (I don't like
    to say amateur!) photographers out there that would wipe the floor with some
    of the paid professionals. Unfortunately I know some of these cowboys too..!

    Craig.
     
    Craig Marston, Jun 18, 2005
    #17
  18. Slack

    DHB Guest

    Craig,
    there are 2 reasons I made the distinction about my being an
    "amateur" photographer:

    1> Correctly or not, I associate a professional photographer as
    somebody who earns a living taking pictures or at least is paid to do
    so on a fairly regular basis. This is not always an indication of
    competence however. As an E.T. (Electronic Technician) I have
    encountered other E.T.'s that I would not trust to correctly or safely
    replace a burned out light bulb! A job title certainly is no
    indication or assurance of competence.

    2> People tend to be more open minded if you come across with
    humility. My ego does not need to be bolstered, so I usually only
    post when I think I have something that "may" be of value to others,
    not to attempt to prove somebody wrong. On the other hand, I am human
    & it does make me feel good when somebody posts back that they tried
    something I suggested & it worked for them or that they found benefit
    in something I offered.

    Just looking for that "win-win" like when I was asked to
    photograph a wedding as a back-up photographer with my DSLR. In total
    they got about 900 pictures & I gave "all" of them to them that night
    on 6 CD's with my blessing to do with them as they wished. They were
    very pleased & wanted to pay me but I refused because I told them, I
    am doing it to improve my skills, if something useful comes out of it
    for you, great, then it's a win-win!

    If properly archived those pictures will be around for
    countless generations to enjoy & or laugh at long after I am 6 feet
    under. And yes I did make mistakes but I also learned a lot from them
    & a lot of the pictures came out quite good, especially the candid
    ones where I had the advantage over the other photographer because of
    being on the sidelines, so to speak.

    Lastly, I have found it a huge advantage at the following
    reception or similar functions, to give a simple P&S camera to a young
    child & ask him or her to go around to each table & take pictures.
    They love it, get some great shots too because they see the world from
    a very different perspective & few people fail to provide a genuine
    smile to a young child with a camera. Again, it's a win-win!

    Respectfully, DHB


    ..


    "To announce that there must be no criticism of the President,
    or that we are to stand by the President, right or wrong,
    is not only unpatriotic and servile, but is morally treasonable
    to the American public."--Theodore Roosevelt, May 7, 1918
     
    DHB, Jun 18, 2005
    #18
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