White balance will be the death of me...

Discussion in 'Beyond the Basics' started by ORourkeK, Jan 11, 2019.

  1. 480sparky

    480sparky Chief Free Electron Relocator Supporting Member

    Joined:
    Mar 8, 2011
    Messages:
    23,385
    Likes Received:
    8,359
    Location:
    Iowa
    Can others edit my Photos:
    Photos NOT OK to edit
    Your color issues might be related to shutter speed and the alternating current cycle of your electrical system. As the voltage peaks, reverses, peaks, reverses..... the lights will flicker. Too fast for the eye to detect, but with a fast enough shutter speed it can catch minor changes in color temperature.


     
  2. Ysarex

    Ysarex Been spending a lot of time on here!

    Joined:
    Nov 27, 2011
    Messages:
    5,957
    Likes Received:
    2,689
    Location:
    St. Louis
    Can others edit my Photos:
    Photos OK to edit
    Most grey cards are made as exposure aids and not specifically WB targets. Instead of a grey card a piece of white Styrofoam (coffee cup) can work well.

    I downloaded the last photo above that you indicate was processed from a CR2 file and WB set from the grey card. The background is white/light grey. I loaded the file in PS and checked it:

    white_balance.jpg

    RBG values are R = 238, G = 238, B = 236. That two point discrepancy is insignificant and that plate is on a white background. On the other side of the plate I got a slightly higher discrepancy (could be a difference in the softbox bubs). The exposure is rendering the background as light grey but that's adjustable. If you're seeing a color cast in the background that's more than imperceptibly slight you may want to consider display calibration.

    Joe
     
    • Like Like x 1
    • Informative Informative x 1
  3. Tim Tucker 2

    Tim Tucker 2 No longer a newbie, moving up!

    Joined:
    Jun 8, 2017
    Messages:
    165
    Likes Received:
    114
    Location:
    Scotland
    Can others edit my Photos:
    Photos OK to edit
    All the above, and a couple of points to add.

    Computers have to deal in absolute colour where a number is a specific colour, but we do not see colour as absolute. Colour is not a property of light but simply how we *see* wavelength. So move away from the assumption that your camera records accurate colour that can be corrected to *absolute* colour by the touch of a button. You camera does not know if the subject is lit by yellow or blue light so has no way of knowing how to *correct* this to the neutral or reference WB. All it does is correct it so it displays a neutral mix of primaries which it assumes is also close to how the colours would look if they were lit by such a light. This is where you use something of known colour such as @Ysarex suggests, if you include something of known white under a neutral or reference WB then it is logical to assume that any shift in colour it displays is also roughly equal to the shift in WB from the reference you are trying to achieve. So:

    1. Calibrate your screen. It is vitally important that you screen is showing colour as close to reference as possible, that the *absolute* colour as described by the number in the computer is being displayed as close as possible to that actual colour.

    2. Look carefully at the actual subject you are photographing rather than just glancing and assuming that the camera will capture accurate colour and somehow magically display this on your screen, (remember your eye corrects and tries to see a neutral WB as well and so will not always either see where WB is slightly off or sometimes will not recognise where it is correct.) It is often the case that the camera is producing accurate colour and it's you as a viewer who's not understanding quite what you see. For instance look carefully at the shadows *before* you photograph and see if there are indeed colour casts in them. Do the shadows look the same on both sides? Is the background actually neutral white or does it reflect a slight cast into those shadows? Are the shadows the same colour on both sides or is there a slight difference in WB between the two lights? Your camera my indeed be capturing the colour accurately and it may be you who's interpreting these slight and accurate representations of hue as colour casts.

    3. Always remember that whatever your camera does the result is seen by the human eye. You cannot subtract this from the equation. There is NO *accurate* colour that is captured by the camera and displayed correctly on a computer screen, there is only colour that is perceived by the human eye. So no matter how accurately you capture and display colour it is always subject to human perception. With the grey that is in the background of the first image, you are trying to interpret that as white and so you are already trying to see and understand the colour as *absolute* whilst deliberately trying to see it as a colour it is not, (white in a computer is 255:255:255, 220:220:200 is grey so you must learn to see it as grey and not white if you are to judge colour accurately). Slight grey will also tend to show the colour shift on un-calibrated monitors more than pure white will and so will be more perceptually *unstable* and open to different interpretations of *correct* than white, (See below).

    Move away from the idea that your vision is absolute and that you see *correct* colour straight out of the box, you don't. Looking at and evaluating colour on a computer monitor is something you learn, (screens or additive colour systems are the most perceptually ambiguous form of colour reproduction). By understanding that colour seen by the eye is perceptual you teach yourself to observe, understand and *see through* perceptual effects rather than glance and jump to the assumption that what you see is absolute and true. By doing this for a year or two with this understanding you will be surprised at just how much more accurate you vision becomes, you will begin to see colour casts that were invisible to you before and you will see casts in shadows and understand where they come from.

    I'm trying to move you away from an understanding that correct colour is all about what the cameras sees and how you adjust parameters in the camera to create accurate colour. I'm trying to move you more towards an understanding that correct colour also includes how you see the original with how your eye corrects WB and how you see the finished image with how your eye corrects that WB. You can use a colour managed work flow to eliminate colour casts on the original, (a predominance of yellow light reflecting off the subject under fluorescent light), and in the reproduced image. This makes colour more stable and more perceptually accurate for reproduction. (EDIT: It works because your eye corrects colour. Your eye tries to remove casts by producing a neutral mix of primaries and this is where the reference WB comes from. If you walk from a room lit by yellow light into an outdoors lit by a very blue light you do not notice the shift in colour because your eye corrects. So the reference WB is not the one that produces *accurate* colour but the one that your eye tries to correct to and so is the one that your eye is least likely to correct from. Therefore the colours produced under this WB are considered to be more perceptually stable and thus is the WB from which reference colour is derived.)

    But consider that you are photographing a subject under fluorescent light, what you see is how your eye is correcting for this, what you are trying to create is an image that corrects for this. What you're not doing is capturing that actual colour displayed under that WB or reproducing it. You're trying to produce an image that shows different colour to that your camera records, colour that is how the system thinks it should look under a different WB. Sorry for the essay but there is no short answer. ;);););)

    ex-1.jpg
     
    Last edited: Jan 12, 2019
    • Like Like x 2
    • Useful Useful x 1
  4. ORourkeK

    ORourkeK No longer a newbie, moving up!

    Joined:
    Dec 30, 2013
    Messages:
    188
    Likes Received:
    49
    Location:
    Hamilton, NJ
    Can others edit my Photos:
    Photos OK to edit
    Thank you all for taking the time to try and help. I really appreciate it. I do not believe screen calibration is the issue. If I go into PS and set the background to 255:255:255 I see "Pure White". My problem isn't that I believe I am seeing the wrong color. I know that the background in those images is grey and not white. The issue is that it should be white. So I need to learn how to make it white every time I take a shot. If you look at the picture with the teacup, it is the closest I have come to achieving 255:255:255. That photo was taken in the exact same place as the other photos. I have a white tent set up where I place all of the items. I am starting to believe that this may be an exposure issue rather than a WB issue. I am using a pretty cheap softbox set that I bought on Amazon. Maybe its time I buy a few flashes or an actual light setup.
     
  5. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    8,643
    Likes Received:
    3,735
    Location:
    Alabama
    Can others edit my Photos:
    Photos OK to edit
    Which is why I make sure the exposure on my target is correct and not in shadow, before I use the dropper tool to adjust WB. If the exposure is off it will have a bearing on how LR adjusts the WB. Even then I use the curve channels to make final color adjustments to an image, based on what I perceive to be the correct WB.
     
  6. ORourkeK

    ORourkeK No longer a newbie, moving up!

    Joined:
    Dec 30, 2013
    Messages:
    188
    Likes Received:
    49
    Location:
    Hamilton, NJ
    Can others edit my Photos:
    Photos OK to edit
  7. Ysarex

    Ysarex Been spending a lot of time on here!

    Joined:
    Nov 27, 2011
    Messages:
    5,957
    Likes Received:
    2,689
    Location:
    St. Louis
    Can others edit my Photos:
    Photos OK to edit
    I suspected this. You don't have a WB issue you have an exposure issue.

    Testing your display for a color cast by setting full white (255, 255, 255) isn't a great idea. Set the color to (230, 230, 230) and look for a color cast -- you should see light grey.

    Moving on: you want your exposure to render the the background full white (255, 255, 255). You have the EC control in the camera you can use to increase exposure and you have post processing controls when you process the CR2 file.

    Problem is you also have white subjects sitting on white paper. If you blow out the paper you'll blow out the subjects. A lighting answer is to light the paper separate from the subjects but that will require some work -- the best solution but difficult.

    In post you can mask the subject and then adjust the background.

    Joe

    plate.jpg
     
  8. ORourkeK

    ORourkeK No longer a newbie, moving up!

    Joined:
    Dec 30, 2013
    Messages:
    188
    Likes Received:
    49
    Location:
    Hamilton, NJ
    Can others edit my Photos:
    Photos OK to edit
    I have been practicing masking now for a couple of hours. I do fine on the top part of the items, but the bottom parts where I have shadows, things get rough.
     
  9. Tim Tucker 2

    Tim Tucker 2 No longer a newbie, moving up!

    Joined:
    Jun 8, 2017
    Messages:
    165
    Likes Received:
    114
    Location:
    Scotland
    Can others edit my Photos:
    Photos OK to edit
    It's not really how you want to proceed. Not only does it take time but you have to be very careful to produce the same output for all images if you are looking at multiple products to be displayed on the same web site. Slight colour differences are very noticeable when you have two images side by side, and nothing communicates that you are not looking at true colour more than slight differences in the white background between images... ;);););)

    What you need is a colour calibrated work flow combined with a lighting system that will produce a slightly over exposed background against a correctly exposed product. For this there are far more knowledgeable members on this site.

    For the colour managed work flow consider using a colour passport. It is a swatch of different known colours and when used correctly will produce a consistent WB adjustment (so your target or finished image has the same consistent WB and look). It is easier and more accurate than adjusting each image individually.
     
  10. Ysarex

    Ysarex Been spending a lot of time on here!

    Joined:
    Nov 27, 2011
    Messages:
    5,957
    Likes Received:
    2,689
    Location:
    St. Louis
    Can others edit my Photos:
    Photos OK to edit
    Don't try and mask a shadow -- just the subject. You're using LR. Use the brush, set it very large and first mask over the entire image. Then switch the brush to erase and erase out the subject. This can still get tricky and become time consuming so back to taking your photo: If I were doing this: the lighting solution is to place the subject on translucent white plexi and light that from behind or lift the subject off the background (shadow issues) so that you can direct lights on the background that do not light the subject. I would use the option in bold.

    Joe

    mask.jpg
     
  11. Designer

    Designer Been spending a lot of time on here!

    Joined:
    Apr 13, 2012
    Messages:
    17,147
    Likes Received:
    4,352
    Location:
    Iowa
    Can others edit my Photos:
    Photos OK to edit
    That is WAY too much work.

    I think your backdrop is white, is it not? Why not simply use that as your WB target? Or if you prefer going through all the tedious work of matching some numbers, just put a styrofoam plate, box, or cup in the first frame (why move the main subject?) and snap off the first shot to give you a WB target. After removing the cup, take all the shots you need using the same exposure settings, and then match away!

    Personally, I just use my WB adjustment tool, and make the backdrop white, and call it good. Takes about 15 seconds for everything I need to do for each photo.
     
    • Agree Agree x 1
  12. mrca

    mrca No longer a newbie, moving up!

    Joined:
    Mar 13, 2018
    Messages:
    315
    Likes Received:
    102
    Can others edit my Photos:
    Photos NOT OK to edit


    Use a color checker passport. The color will be correct. Not close, dead on. You must be working on a properly calibrated monitor as well, that includes brightness. Get a calibrating system that dials in brightness. If you ever are going to print, I never was satisfied with what I got with spyder calibration, but with the i1studio nailed my monitor brightness, color and for printing, no more laborious test prints, it creates custom profiles that produce prints matching my monitor. It includes a small color checker target to nail color. It is one of those buy right once rather than buying twice.
     

Share This Page