White office A4 paper for White Balance?

Discussion in 'Open Discussion' started by spacecreature, Feb 4, 2015.

  1. spacecreature

    spacecreature Mu-43 Regular

    52
    Dec 7, 2012
    Hey guys,
    Ok, I have been using a grey card I bought from China for my WB, and frankly I am beginning to question how neutral it is...coz the results are looking a bit weird...so I was wondering, can one just use a regular white A4 office paper to do a custom white balance on, or is it also not neutral? I mean perhaps its a bit more blueish than what white is supposed to be,..or is it??

    The grey card is also tiny, and I struggle to get it all in the image for when I want to do a custom white balance in camera using my OM-D E-M5 (where you shoot an image, then tell the camera to set that as WB reference). and when i use it instead in post to color correct, I am not so impressed with the precision in colors I am getting..so...

    Hopefully that will be a temporary fix, while I order a fancier color checker:)

    Tnx in advance...
     
  2. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Promit Roy
    It may not give you clinically perfect WB, but sure, why not. I frequently pick any arbitrary white thing in the frame to WB in post, and then adjust to taste from there. Another thing you can do is go get some of those free paint swatches they keep when you're painting your house, and find one that gives good results.
     
  3. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    The whitening agent in white paper causes it to emit frequencies like this:

    Slide29.GIF


    Regarding your 'weird/unimpressive' results with your grey card, can you explain a bit more please?

    Also, is your monitor calibrated?

    cheers
     
    • Like Like x 1
  4. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    As an aside, I have noticed that my old grey card is slightly blue compared to my Spydercube (which I trust). So maybe a cheapie grey card is not the best idea.

    This one should be trustworthy. But smallish.
     
  5. LowriderS10

    LowriderS10 Monkey with a camera.

    May 19, 2013
    Canada
    When I was a reporter (newspaper), my TV reporter friends were constantly asking me to hold up my notebook or random pieces of paper so they could set their WB...so I'm guessing that works just fine. :D
     
  6. jyc860923

    jyc860923 Mu-43 Hall of Famer

    Feb 28, 2012
    Shenyang, China
    贾一川
    I use 4*6 photo paper sometimes, and I guess you could print it to various tints to affect your WB deliberately
     
  7. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    If you're shooting in odd, or mixed lighting, it's vastly better nothing. For RAW it will give something that can be used for a one click WB (shoot a picture with it in the frame). For JPGs it will give a very good WB, and it's even more critical because JPGs don't you much to work with to correct WB.
     
  8. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Go to a hardware store and pickup some grey paint sample cards (the cardboard things showing what tint your paint will be), they're generally pretty close and there's no optical brighteners to deal with. The only downside is they're sometimes glossy compared to a 'real' grey card (which is more matte).
     
    • Like Like x 2
  9. spacecreature

    spacecreature Mu-43 Regular

    52
    Dec 7, 2012
    Ok thanks good to know, I thought there could be such a problem, so A4 paper is out :)

    What I mean is my grey card is actually 3 in one, so one white, one black and one grey. And supposedly they are all neutral right? but if i click in post on black, then white, then grey, I get 3 different results, thats why I am not so sure which is correct..

    My screen is well....ehem ehem , just clearing my throat hehe, ok I did not calibrate it like Im supposed to, I was about to buy a calibration device but used that money for something else, u know there are tons of stuff to buy! but you can say it is somehow calibrated because I went with the best factory calibrated one, it is an LG monitor with somewhat accurate colors with a special profile for photography :) and other people's photograph look accurate too ..BUT even if it wasn't shouldnt all three colors give the same result???? Given they are all neutral?

    Plus my OMD camera has a one touch custom white balance, where you shoot a card and set it as WB. In the manual it says to shoot a white card, but I have always thought to use a grey colored card as it is less likely to clip or somethingetc.. so which should I use?

    Tnx again:)
     
    • Like Like x 1
  10. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Assuming they're neutral the camera cannot tell the difference between white, grey, and black - it will assume it needs less exposure for the white and more for the black. An E-M1 can do up to 1/4000th of a second using electronic shutter in normal use (this is per pixel exposure for a full sensor readout, the scan time is far higher and it can read lower resolution at far higher speeds (it needs all of this so the EVF doesn't clip)).

    The main advantage of more expensive grey cards is they remain neutral under more lighting conditions, they achieve this by reflecting the same amount of light of all the various wavelengths (no one colour more than others). The reason grey is used rather than white or black is the amount of light reflected is consistent between different light sources, it can be balanced. It's very hard to achieve a neutral white as it may reflect more blue or UV or just have spikes due to the various compounds used to make it, black has the same problem as what appears black to our eyes can actually be very bright in IR wavelengths (the black paint on many aperture blades causes issues when imaging at IR wavelengths as it actually becomes highly reflective). Another example of this would be Coke - it's a sort of reddish brown at visible wavelengths, however at IR it's clear and see through. Titanium dioxide is highly reflective and thus very bright, however it absorbs light in the UV range (and would thus probably appear black if imaged only using UV).

    A grey card is neutral to a fault - in theory it's always going to appear as a 18% grey with the "correct" exposure no matter which wavelength you image it with (real world use is never perfect, however this is why many people use colour checker wallets with a few dozen swatches).




    It's all moot without a colour balanced monitor, I wouldn't say the "correct" white balance is always desired. Depending on the mood you may want the picture to take on a colder or warmer tone and without a balanced monitor you cannot tell what it will actually look like (I once edited an entire series in a rush to meet a deadline, the computer I used had Flux installed and I didn't realize - every single picture was cold). I would look into getting a Spyder or some other device like it (they're cheap compared to other equipment for how much actual improvement can be seen in pictures, a new lens or camera may or may not improve results - a colour calibration device always will), it's a good investment as they last years and years.
     
    • Like Like x 2
  11. T N Args

    T N Args Agent Photocateur

    Dec 3, 2013
    Adelaide, Australia
    call me Arg
    If tftcentral have tested your monitor model, you could try downloading the profile they calibrated for it. Doesn't always work: monitors vary individually.

    The man's an oracle. Best listen.

    ==

    But maybe you have good colour and no real problem, as explained by eteless use the grey one not white or black.
     
  12. spacecreature

    spacecreature Mu-43 Regular

    52
    Dec 7, 2012
    Ok thanks all, I guess will stick with the grey card for now, until i buy an x-rite or something. Thanks again.