Chasing perfect color, and common myths about white balance

The previous article on the inexact science of color and emotion dealt with why color was important, and how we can use it as a tool to alter the mood and emotional response of the viewer of our photographs. This article explains how we get there.

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Sandwiches. Did you know greens are heavily affected by the yellow channel? Nikon D700, AFS 60/2.8 G Micro

Although highly saturated color is visually striking, and B&W images are timelessly classic and elegant, there are a lot of times when neither is appropriate or an accurate representation of the scene. I’ve recently realized that I like accurate color above everything else – saturation control then becomes a matter of seasoning to taste. Color accuracy is actually quite critical when it comes to things like food – if the color of cheese or lettuce is off, it just looks moldy or unfresh. This is definitely NOT good for commercial work! My recent work is what I’d call in a ‘natural’ style – the color, saturation and hues are as close to my perception and remembrance of the scene as possible. I’ll do some shifting of white balance to make things warmer or cooler as required, but not a huge amount because it can do some very strange things to tonal accuracy.

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Scarlet Ibis. The red in is plumage is due to pigments in the shellfish that forms the majority of its diet. Leica V-Lux 3

Skin tones are perhaps the most difficult to replicate accurately; this is because skin is both reflective of ambient light (easy for the camera to capture) and emissive – we’re warm, and there’s some passive IR radiated by warm objects. Although modern cameras have very effective UV/IR blocking filter packs, they also produce (in my opinion) slightly dead-looking skin tones. I actually liked the skin tones from the Leica M8 for this reason, which was notorious for having perhaps the weakest UVIR filtration of any camera on the market – to the point that to get accurate blacks you’d have to use a UVIR filter on your lens.

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Black fabrics in the sun are notorious IR-emitters. Leica M9-P, 28/2.8 ASPH

Other objects that are notoriously difficult to reproduce accurately are flowers, some animals, and some fabrics. Again – this is because of the way they interact with the near-UV and near-IR spectra, which affects the way our eyes perceive color (though we can’t see UV or IR directly unlike some animals). To date, there is no camera that accurately reflects the spectral response of the human eye – and I suspect it might be very difficult to make one, because the filter pack would have to be calibrated to transmit or cut out a certain amount of each wavelength. It’s much easier to make a filter that cuts out everything above and/or below a certain wavelength. Throw in the added complication of mixed light sources, and you’ve got a minor nightmare.

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Colors. All of them. Which one do you balance for without shifting the others? Answer: focus on your subject – in this case, skin tones and blacks. Olympus E-PM1 Pen Mini, 45/1.8

So what can we do to achieve perfect color?

First clarification: we are not trying to achieve perfect spectral reproduction; we’re trying to achieve perfect perceptual reproduction. It’s not quite the same thing. Basically, you want to get to the starting point of being as close to what you remember seeing as possible, then work from there. That way, you know that all of your tweaking isn’t going to create some strange shifts in certain parts of the tonal spectrum.

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Chilis. Nikon D700, AFS 60/2.8 G Micro

White balance is inextricably linked to color. And there are some important things one has to bear in mind:

1. You have to get it right first time if you’re shooting JPEG. There just isn’t the tonal headroom in 8 bits to be able to make anything other than minor channel adjustments and not encounter posterization or weird hue shifts.

2. Manual white balance and a piece of paper are your best friends.

3. If you’re shooting RAW, white balance is less critical, but if you blow a channel, you’re not getting it back. Usually reds and yellows are the first to go. With earlier cameras, you might have to underexpose by as much as two stops to maintain tonal detail in the reds. I think it’s something to do with IR-sensitivity, the effectiveness of the filter pack over the top of the sensor, and how the red pixels respond very strongly to IR pollution.

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Cigars are one of the most difficult colors to get right. I don’t know what it is about the tobacco leaf, but that rich, deep brown hue requires a lot of work to perfect. Nikon D700, AFS 60/2.8 G Micro

4. White balance does affect exposure. This isn’t immediately intuitive; the reason is because if you get it very, very wrong, you’ll find that after correction, the dominant colors in the shot will shift, and the sensor may not have gained up enough at the extreme ends (red or blue) resulting in underexposure – most likely. You can to some extent recover this in post, but the bigger problem is that you’re going to land up with a very noisy image – the blue channel is generally holds the most noise for most cameras as it is the least sensitive due to the laws of optics, photon energy and filtration…but I won’t go into that here; complex quantum mechanical formulae are beyond the ability of my blogging software to input and display. :)

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Prayer wheels, Nepal. Nikon D700, 24/1.4 G

Bottom line: shoot raw, and get in the right ballpark. Small adjustment are fine, and you can never get it 100% right all the time with a manual balance because ambient light is always changing. AWB works reasonably well on most cameras these days, but you have to watch out for the very warm light sources. I was told by several people in the camera industry that it was a conscious choice to leave the yellow/red components in the tungsten AWB because people expect the light to be warm (back to perception) – and having pure whites just looked odd to most consumers. I can attest to that as a lot of my students have asked me why the color is so blue when shooting indoors! Although I can’t say whether it’s a visual expectation on the part off the photographer, or whether inaccurate white balance is something they’ve come to expect because it was inadvertently dictated by the industry.

I’ve been playing with a handy little tool recently called a WhiBal. Basically, it’s a very, very accurate neutral gray card. I’ve found there are two ways to use it – one, take a shot under AWB with the card in the frame, and use that as your reference frame; eyedropper tool WB from the card in ACR, then sync white balance between the remainder of your files. Note that these two methods only work when your lighting is consistent from frame to frame, i.e. under studio conditions. The other option is shoot the card under the lighting conditions you’re going to use to set the preset in camera; I find this works better because all of your frames are automatically synced from the shoot. And if you’re using the same setup – as I do for watches – I can basically do it once and just leave one of my manual presets to match my flash and diffuser combo.

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If any of you have shot purple flowers, you’ll know they’re notorious for shifting towards blue: that’s because of the UV reflectance. Flowers have UV and IR reflective pigments to signal to other animals – in this case pollinating insects and birds – that can see UV and IR.
Nepal. Nikon D700, 24/1.4 G

Next, make the tweaks – in your RAW converter, (I use ACR 6) perfect your white balance. Use the eyedropper tool on various gray areas in the scene until, it looks close to what you remember. (This is another reason why I like to process as close to immediately as possible: you might forget what the originals scene looked like, or any processing ideas you might have had at the time). Don’t worry if the eyedropper tool doesn’t get it right; you can shift the color temperature and hue sliders a little until you do.

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This blue is one of the most difficult colors to get right. What makes it so appealing as a car color – the fact that it changes a lot under different lighting conditions – also makes it a royal pain to photograph and represent accurately. The honest truth is that I have no idea what RGB value this actually is, because it’s both reflective and in many spectra. Nikon D700, 28-300VR.

Open your file, make whatever contrast adjustments you need to – curves/ levels – then only use the Hue/Saturation tool to adjust the individual channels. Using curves inevitably shifts the saturation and hue slightly – there’s no way out of that – so you’ll need to bring back the individual channels. For instance, if it’s predominantly red and you used a curve that darkened the image, you’ll have to compensate for that by reducing saturation and increasing lightness slightly in the Hue/Saturation tool. There is no exact science to this – it’s all about experience, perception, and having the most accurate monitor you can find.

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Remember what I was saying before about shellfish and birds? Nikon D700, AFS 60/2.8 G Micro

Each camera has a different filter pack and spectral response. Even though manufacturers try to keep the color output consistent from model to model, there will be differences. The D3100, for instance, has a crappy color gamut that I was never happy with – much like the NEX-5 – however, the D700, D5100 and D7000 are all pretty similar. The D800 is close, but even more accurate and with a wider supported tonal range out of the box. The M8 with UVIR filter, M9 without and S2 are almost identical. Since I use a whole bunch of cameras – at the last check, Leica, Nikon, Olympus and Ricoh – I’ve created individual color profiles for each camera in ACR and saved them as camera defaults. The look I like is somewhere between the tonal richness of Leica and the warmth of Olympus – perhaps Olympus + Zeiss glass describes it best. Oh, and different lenses have different spectral transmission characteristics too, just to make life more interesting. Your personal preferences will almost certainly be different because each individual perceives color differently. But I suggest that if you have the time, this is a worthwhile exercise.

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The challenging pale but saturated lightness of macaroons. Nikon D700, Carl Zeiss ZF.2 2/2.8 Distagon

One important final note: all of this is in vain if your final output use is extremely limited gamut or highly compressed (*cough*FACEBOOK*cough*) – all of the additional tonal information you tried to save is going to be lost and compressed to hell. Some browsers (Safari) and photo sharing sites (Flickr) are better than others because they are color profile aware and don’t compress images, but the issue then becomes monitor accuracy. So unless you know the final output method and have some control over it, it’s very tricky to ensure that everybody is seeing the same thing. And printing is a whole separate blog on its own…MT

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Images and content copyright Ming Thein | mingthein.com 2012 onwards. All rights reserved

Comments

  1. I just bought a GX7 to complement my E-M1 and like them both very much but I prefer the colors from the E-M1 and I want the GX7 colors to look as close to that as possible.

    I use LR and find 3 possible ways to make these color adjustments:

    * Whitebalance (has the downside of needing adjustments for each different scenario)
    * Color (also has the downside of needing adjustments for each different scenario)
    * Camera Calibration Color adjustments (will hopefully be the same for different scenarios!?)
    * Create a custom profile for the Calibration Color adjustments (is that possible?)

    What way would you choose?

  2. liramusic says:

    Before I sign out, may I ask one more question. I promise to sign off then, at least for today. What a great resource this is. How do you feel about Nikon’s 35mm f/1.4 lens? I have a feeling that even if I use CS6 software and hence DNG converter with the NEF files, I still think that this one lens, if I could afford it, is one of the great lenses of all time? They warn though of fringing. Finally, I have a feeling that this post should have been to a separate thread. Thanks for patience with me. My general situation is low light, incandescent, more or less pub kinds of settings. This rather than studio settings. I like prime lenses and am always am faced with highly-mixed lighting sources.

  3. liramusic says:

    Great narrative here. Yet so much talk of blue flowers, or purple. Far, far more commonly for me is the boots-on-the-ground issue of deep orangish-yellow skin in dim incandescent lighting such a small jazz club where lighting is mixed and sort of flat. I want a light meter to measure kelvin and dial it in. Why doesn’t anyone seem to talk about that? If my frustration comes through in my writing, “who cares” what the reflective light is. I have nice equipment, both the d700 & the d600. Maybe a $400 meter ought to be next?

    • liramusic says:

      BTW, yes, I so much agree that some yellow is expected and absolutely needed. I wanted you to know that I agreed with you. As to why, it is aesthetics or something neurological? In my post above I think that I am proposing to use a light meter for kelvin temp and then bring it a little bit warmer. Is this a perfect solution, no. That leaves light levels overall to be my problem when I take the picture. Ok well, I checked the notify-me box. It will be an honor to read your ideas about light meters and kelvin temp.

    • There are color temperature meters, but they’re horrendously expensive…

      • Why the feeling that you need a Light Meter to solve your problem? Unless you understand how to apply the information shown on your Meter to make Flash and other exposure adjustments for a better than satisfactory exposure, then what is more important is to arrive at the correct white balance for every change of scene existing within the same location, Dance Hall, Pub, Theatre Stage, etc.
        Having an “Eye” for such changes in lighting, colour temperature, etc, is what will guide you to acquire almost-perfect shots with every change of scene. The key is to establish WB presets as you encounter 1 or 2 specific scene differences that you have to shoot interchangeably.
        Mario

        • I don’t, and I never said I did. I don’t use a meter even when shooting slide film.

          • My apology Ming Thein. My reply concerning a Light Meter was in response to Liramusic’s comments and question above.. re.quote: “In my post above I think that I am proposing to use a light meter for kelvin temp and then bring it a little bit warmer. Is this a perfect solution, no. That leaves light levels overall to be my problem when I take the picture”.

  4. Great stuff as usual MT! I have a question about your suggestion, when shooting RAW, to get the WB ‘in the ballpark’. It’s something I’ve been wondering about for quite some time, and must admit I’ve been too lazy until now to empirically find an answer to it. When shooting RAW, does the data captured from the sensor actually change with different WB settings for the same scene? I would think not but I’ve never had this confirmed. I always check my RGB histograms to make sure no channels are blown, and never bother with finetuning the WB settings, just using the standard settings for flash in studio, sunlight in sunlight, cloudy in overcast weather etc.
    On a side note, I once did experiment with my old D80 back in the day to make 3 different exposures of the same scene, to get each channel filled as best as possible, then extracting the channels of the 3 files to combine them into 1 single file, the same way Prokudin-Gorski used to work. The results were amazingly accurate and rich colors, but the workflow is obviously very convoluted.

    • So long as you don’t clip color channels, the WB info doesn’t fundamentally change that much. But if you get it very wrong, you’ll find that the channels that have to be boosted will be very noisy. Try it and see – shoot shade and incandescent under tungsten lights with correct exposure, equalize in raw and look in the shadows. Dynamic range and color palette of the newer 14-bit cameras is sufficient that you don’t have to do this anymore. Color accuracy gets better with every generation.

      • Aha, so the light meter takes the WB settings into account? Will definitely try that out! Thanks!

        • It should do with the Nikons as they use an RGB meter, not sure about other cameras. Definitely for mirrorless/ LV-only since they meter from the sensor directly.

  5. Ming, great advise, as always! I am amazed by colors in your photos! Excellent!!!

  6. Excellent editorial sir. I found this web page by chance while googling for a description of the colour called Ming.
    I have not read such a comprehensive, technically academic, yet practical and pragmatic approach to a topic which I describe as “All encompassing”. For 1 aspect (of light) can not be explained without involving the other, neither can any be adjusted without having repercussions with others. When we keep in mind as we photograph or video-shoot, all the variables within the environment that impact on our subject or scene, we are better informed and can make better selections, with better exposures.
    I have learnt how to get accurate results over previous years of trial and error and comparison, when videotaping with Hitachi, Panasonic, and Ikigami broadcast cameras. Then I applied those principles when using my Canon and Nikon still cameras (both analog and digital). The fundamental principles hold to date with digital technology.
    The most important preset for me was to establish a “realistic” White-Balance of the scene. And the most important consideration then was colour temp. coming from the various light sources around; I always pick the one that most highlights the subject, or most critical part of the picture. I then follow up with exposure adjustment; then Click/Shoot…. Weaker lenses respond less accurately at lower colour temps. It is important to know the temp range of Fluorescent versus Incandescent, early morning, evening time etc. and the performance of your lens, not so much the camera. I have tried this same approach using a “piont and shoot” Canon A1000 alongside a Canon Rebel 2011 series and the results were comparable in terms of colour balance and Black Level; Then, you can more easily achieve an enhanced quality picture with your post production software, some of which techniques you described.
    Oh, I forgot to mention… there is something about viewing through your lens (still of video) in Black & White, that shows a different perspective of exposure and colour balance as it relates to White Balance. Whenever I was shooting with the wrong shutter or aperture setting, or inaccurate white balance setting, the Grey Scale of the Viewfinder looked off, or muddy, or like black & white, or somewhat coloured. This helped a great deal as a guide check when using more up to date cameras that provide a full-colour viewfinder with switchable Grey Scale viewing.
    I look forward to your response to my lengthy contribution, and i hope it proves be useful to your readers.

    • Thanks for your thoughts. I don’t I’ve got a color named after me (or at least not to be best of my knowledge). Agree on realistic WB – if you blow a channel, you’re not going to get it back regardless of whether you’re shooting raw or not. Color and tonal map are the biggest giveaways usually to sensor size/ P&S vs DSLR etc – most people don’t bother to take any care with the color processing for compacts.

      I don’t set my cameras to B&W, I guess I’m just used to watching the luminance values and ignoring everything else. A holdover from my film shooting days, I suppose.

      • liramusic says:

        Not only is a color named for you, an entire historic dynasty! Maybe you have an inheritance waiting to be claimed. I am being funny. Well but yes, Ming Pottery with its cobalt blue under glaze.

  7. Excellent article. Must be bookmarked:)

  8. Thanks for this great article Ming. Perfect timing as I was about to email you about your colour management. I myself seek (aimlessly try) for the balance of the correct colour balance. You mentioned that white balance correction affects exposure. Do you recommend adjusting white balance prior to making exposure correction on post processing? Also, if there is one step that will get you close to the perceived colour, will it be the eye dropper tool? Thanks again for all the helpful information on your site.

    • No problem. Yes, adjust WB first then exposure – it’s just easier to gauge as you’re going to have to adjust it anyway. WB eyedropper on the *right* bit of the image will go a long way to getting your desired color balance.

  9. It’s good to read about how crappy the D3100 color is. I gave one to my father and I was looking his pictures and complaining about the greenish sky. You have to underexposure to avoid it .
    Another weird color gamut is the D300.
    I like the D7000 but i think that there is a predominant green tone in some tungsten light conditions. And I saw some D800 imagens that gave me the same impression.

    • The D3100 is atrocious. It shares the same sensor as the NEX5 and that was atrocious too. I don’t have the green tint problem with the D800/E, nor did I have it with the D5100 – but then again I don’t use any of them under tungsten light much, so you may be right.

  10. Great Article Ming,

    Have you considered using a tool like X-Rites Color Checker Passport? to help achive a base color under the specific lighing conditions? Its bit more than just whitebal

    • Don’t need it. Between the whibal and my custom profiles, I can get what I want most of the time…and when I can’t, it’s usually because of mixed lighting sources.

  11. Mikko Moilanen says:

    Thanks again of the excellent article and photographs.

  12. Excellent article, Ming.
    The colors in your images have a signature of your own, silky, smooth and attractive. Would you mind to give a step by step tutorial on how to create the color profile as you mentioned below?
    —- I’ve created individual color profiles for each camera in ACR and saved them as camera defaults. The look I like is somewhere between the tonal richness of Leica and the warmth of Olympus – perhaps Olympus + Zeiss glass describes it best. —-
    Thanks for sharing the knowledge.

    • Thanks Wayne. It’s very difficult to describe in person – color calibration is something you have to do by eye. The best description I can give is use the eyedropper tool on the white balance, and then adjust your HSL sliders until you can replicate accurate color but with WB set to AUTO. This obviously takes many, many iterations because different cameras experience different AUTO WB shifts under different scenarios.

  13. Vitali Shkaruba says:

    A good short article on this complex topic, Ming.
    Two questions that I’m asked the most are 1. “Why blue (-ish) flowers on my photos have different color than what I saw while taking the picture?” and 2. “Why is my image that I took late in the evening has such a strong blue tint?”
    One of the big Aha moments for people seems to be when they realize that their camera’s AWB suppose to work Ok in a range of around 3500-8000K (fluorescent been even more tricky). AFAIK it is written in most camera’s manuals, but few will notice those numbers and correlate them to real life usage until they run into situations where AWB doesn’t give them the expected results.

    • Thank you. To your questions:

      1. Blue flowers are heavy UV/ IR reflectors; that’s to attract birds whose visual spectrum extends beyond ours. Sensors don’t match our eyes, which mean that you get UV or IR pollution in the blue and red channels respectively. (Whether it’s UV or IR or both depends on the flower). I’ve yet to see ANY camera that can get this right; blue flowers are one of the first things I test shoot when getting a new camera.

      2. The strong blue ting is because you’re perceiving around 6000K, which looks warm, but the light temperature is around 8000-9000K – evening WB is pretty much the same as shade; the camera sees closer to the true color which means you lose that warm glow. Dial in daylight WB manually if you want to retain the warm hues. The reason evening light is so cool is because the sun shines through the atmosphere at a very shallow angle by that point, which causes some filtration of the spectrum. You get the same effect in the morning, too.

Trackbacks

  1. [...] is by shifting the white balance in either direction by a small amount. Note that you have to start out from an accurate zero point to begin with to avoid shifts in certain [...]

  2. [...] ones would not. It is therefore the responsibility of the photographer to ensure that color is as accurate and faithful to the original subject as possible. The alternative is to shoot in black and white; this has the effect of removing the psychological [...]

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  4. [...] firstly the basics of the principles of composition, color theory and psychology, the importance of perfect color and how to achieve it, and finally, deconstructing lighting under several increasingly complex scenarios – one [...]

  5. [...] time, after reading Ming Thein’s very recommended article about perfect colours, I tried to get those punchy colours and deep and rich blacks which I love so much in his pictures. [...]

  6. [...] Perfect Color – Today, 08:23 AM Chasing perfect color, and common myths about white balance Some great pointers. I had especially noticed how the wrong WB can greatly affect your shot, even [...]

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