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Arising out of my Digital Disasters blog, I've had some inquiries asking if I could elaborate more on white balance and ways to achieve a more correct white balance. For me, white balance is just a small part, albeit a significant one, of a fully colour managed workflow and unless you have taken steps such as calibrating and profiling your monitor, correct white balance will only take you so far.
The first thing to get out of the way is what exactly is meant by "correct" white balance. Landscape photographers will rarely want "correct" white balance. Just imagine how uninteresting a magnificent sunset image would look if it was correctly colour balanced. However, I think for people photography in general, the aim ought to be to get the skin tones correct and in order to do so we must start with the correct white balance.
I'm not going to go into any real detail as to what exactly white balance is but for anyone that's interested in learning more, one of the better tutorials that I've come across is the Understanding White Balance tutorial over at the Cambridgeincolour.com site.
There are several ways of obtaining correct white balance in your image. By far the easiest method is to simply use the Auto White Balance feature of your camera. This works surprisingly well in the vast majority of cases, but just like auto exposure, it's likely to let you down at the most critical moment, so I wouldn't advocate using this method.
A slightly more accurate way of getting the correct white balance is to use one of the several presets provided on most cameras - Daylight, Shade, Cloudy, Flash, Tungsten, etc. These work quite well too, but shouldn't be used blindly. For example when using studio flash, you can't really be 100% sure of it's colour balance because as flash tubes age, their colour balance changes.
Finally we come to custom white balance and this is by far the most accurate method. There are several ways to do this, some better than others, but the objective is the same - to set the correct colour temperature based on a "standard" reference reading.
One method involves photographing a white or grey reference card and using the resulting image to set the camera to the correct white balance. If you don't know how to do that, read your manual (sorry to be blunt). Another method involves purchasing an expensive piece of plastic (Expodisc makes one and there are several other manufacturers) and placing it in front of the lens, pointing the camera at the dominant light source and taking a shot and then setting the custom white balance as you would when using the white or grey card method mentioned above.
While these methods of setting custom white balance work, I find them time consuming and awkward to use and at the end of the day, human nature is such that if something is a pain in the butt to use, you can be sure that pretty soon we won't be using it as much as we should, if at all.
My own personal favourite is to get the white balance correct after shooting. Whenever the light changes or the subject moves into a new environment, I need only take a quick shot of my white balance reference card (I use a WhiBal card) and continue on shooting. Or if I forget to take the reference shot at the start of the sequence, I can take it mid-way or at the end, it really doesn't matter. Then I open up the images in my RAW converter and for each series of images I locate the white balance reference shot I took and use the White Balance Eydropper to sample the white balance reference card. Once that is done, I apply the setting to all other images in that particular sequence and I instantly have the correct white balance for all of the images. I like to shoot with my camera permanently set to Flash White Balance as that gives me a look most like film in terms of what happens with the colours if, for example, shooting indoors under tungsten light.
This technique of shooting a white balance reference card is quick and easy to do, particularly if you shoot RAW format images. However, it also works well with JPEG images, provided the difference between the correct white balance and the photographed white balance is not too great. All you need to do with JPEG images is open the Curves Tool and using the middle eyedropper, click on the grey reference card. You can then save that curve and apply it to the other JPEG images from that same sequence.
Hopefully this is of some help to someone and if there's anything you don't understand, let me know and I'll do my best to clarify it.
- Thorsten.
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tmerz@gmx.net
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| POSTED BY: SeanMcC on 09/05/2008 06:04:45 |
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Depending on the brand of lighting you use, the color temperature of the lights can change as you increase or decrease the power of the light. So if you change the setup, you'll need to take another WB reading, by any of the methods Thorsten has mentioned.
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The more I learn, the less I know.
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Hi , Great and very usefull post.....
I my self use a Greycard when ever i change my lightsetup and then make the changes in Lightroom ....for me the most easy way to do it of course shooting in RAW also helps. Good to see more posts like this.... PB
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Photographer Dublin
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Cracking site Thorsten, looks like my day is set reading, lol. I have spent the last 2 hours on here already. Super reference site for all!  Thanks Martin
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What you see depends on what you're looking for!
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| POSTED BY: Nexus on 09/05/2008 09:16:50 |
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I use the expodisc method but I don't point it at the dominant light, you set the lights up, take a meter reading, set the cameras exposure and then set the white balance by pointing the lens/expodisc combination where the subject will be.
Great post!
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Nexus wrote:
I use the expodisc method but I don't point it at the dominant light, you set the lights up, take a meter reading, set the cameras exposure and then set the white balance by pointing the lens/expodisc combination where the subject will be.
Great post!
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Supposing your subject is wearing a particularly strong colour, what do you do then? In fact, that's something to consider with any custom white balance reading one is doing. For example, if photographing in a room with strong coloured walls, then that's going cause an inaccuracy. The other thing to be wary of is if taking a custom white balance reading using a grey card method is to ensure that it's not affected by anything you might be wearing such as the woolly red jumber you got for Christmas  . This applies to metering as well - you'd be surprised how many times I've seen people go up to the subject to take an incident light meter reading and they stand between the meter and the key light! And then they wonder why their images come out overexposed!
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tmerz@gmx.net
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| POSTED BY: Nexus on 09/05/2008 09:49:41 |
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ThorstenM wrote:
Supposing your subject is wearing a particularly strong colour, what do you do then?
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The custum WB is shot without the subject in the scene, in my case 10 mins before they arrive.
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| POSTED BY: timcully on 09/05/2008 10:35:10 |
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Great post Sir, I will start reading
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www.timcully.co.uk
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ThorstenM wrote:
I like to shoot with my camera permanently set to Flash White Balance as that gives me a look most like film in terms of what happens with the colours if, for example, shooting indoors under tungsten light.
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Confused here... Surely you mean "SUNLIGHT" white balance? Thats what I was taught, as it covers a greater range? Pete.
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Mako
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makoimaging wrote:
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ThorstenM wrote:
I like to shoot with my camera permanently set to Flash White Balance as that gives me a look most like film in terms of what happens with the colours if, for example, shooting indoors under tungsten light.
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Confused here... Surely you mean "SUNLIGHT" white balance? Thats what I was taught, as it covers a greater range? Pete.
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There are a number of things to keep in mind here. First, there is no "range" when selecting a white balance preset as they are set at specific colour temperatures. For example, the pre-sets on the EOS 30D are as follows: • Auto (3000 - 7000 K)
• Daylight (5200 K)
• Shade (7000 K)
• Cloudy (6000 K)
• Tungsten (3200 K)
• Fluorescent (4000 K)
• Flash (6000 K)
• Custom (2000 - 10000 K)
• Kelvin (2800 - 10000 K in 100 K steps) Then, there is the fact that I ultimately do a custom white balance as described earlier above and using a pre-set is just a starting point. Whether I use Cloudy (6000 K) or Flash (6000 K) doesn't really matter as they are both the same. But being used to shooting transparency film, I've found that using a preset in the 6000 K range enables me to get a similar look to what I'm used to seeing on transparency. Of course, this won't work for everyone, so you need to make your own tests and decide what works best for you. So, Pete, I guess the answer is that if a "Sunlight" setting works for you, and gives you the consistency your looking for, then there's no reason to change it.
Incidentally, one aspect of white balance I haven't touched on here is the fact that your in-camera white balance setting influences your histogram. However, that's a whole new, more involved, discussion which is better discussed on a new thread.
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tmerz@gmx.net
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