What kind of conditions? A wedding, or more controlled conditions, etc? For controlled conditions I use a White Balance card(not a grey card), which is in effect the same as Custom WB, and it gives pretty helpful starting points. Oh, I'm absolutely assuming RAW.
I'm always surprised by the resistance to a proper white balance card. Anything else will not behave the same in different types of light. I've tried everything from coffee filters to grey cards to any number of white things, and they don't work as well.
And it is not like the proper item has to be expensive.
I use either a whibal reference card or more recently, the X-Rite Colro Checker Passport. With the color checker passport I can profile the camera as well as set white balance and also have some reference patches for tweaking white balance i na specific direction for more pleasing results than neutral always produces, and finally there is a large whlight gray target you can use for setting a custom white balance on your cameras.
The Datacolor Spyder Cube is also supposed to be very good, I just don't have one.
The Expodisc hasn't let me down yet and it's pretty easy to use. One nice thing about it is I keep a "Studio" profile in the menu bank with this custom white balance. Since my Elinchrom's are so accurate, even if I forget to do custom WB, it is rarely a problem.
Most often WB problems aren't the method for setting the WB but rather the fact the lighting is mixed. That's nearly always the case indoors when flash is used for color photography.
In mixed light the most effective solution is to gel the flash to match the ambient to the two match more or less seamlessly. Perceptually we key more off what is in the foreground and more on the tone of faces and objects of known color than anything else. So even when I gell my flash I set custom WB off a gray card, then shoot another one with a color target on it after setting WB as confirmation / reference when editing.
Setting the Custom WB based on the gelled flash, not the ambient background ensures that the faces in the foreground the flash is illuminating are rendered neutral. Starting from neutral makes it easier to make decisions about tweeking the WB for effect when editing. Custom WB doesn't affect RAW capture, but it will make the previews on camera neutral and closer to what will be seen in the RAW editor when the file is first opened.
When I can't do custom WB I pick the nearest pre-set and try to put a gray card in a test shot. That allows me to correct the shot with the card with the eye dropper and then copy the adjusted WB settings to the other files. If I can't put a card in a test shot then I just find a file with some neutral gray value, click correct on it, then use the settings from that file to batch adjust the others.
The goal isn't "perfect" color, but simply to have consistent WB shot-to-shot. For that reason I never use AWB which recomputes WB for each shot based on the brightest non-specular highlights in it. AWB works on the assumption the brightest highlights are in fact white. It works OK when the there is a white shirt or wall in the photo, but not so well if the brightest area is not white.
WhiBal makes a big deal about how perfectly neutral the cards are, but in practical terms that isn't critical because the best looking color balance in photo perceptually is seldom a clinically pure neutral balance. Any reasonably neutral target will serve the purpose of providing a consistent baseline for color management. The goal is consistency, not neutrality.
Portraits look better perceptually when they are a bit warmer than neutral. Color also conveys mood and triggers emotional reaction. If you want the viewer to shiver (and smile an the same time) when they see a naked woman lying a snow drift you'll want to bias the WB on the photo towards the cool side. She might actually be shot lying in fake snow in a studio and shot holding a gray card for with perfectly neutral WB out of the camera, with the decision how to bias the color cooler made later when adjusting the RAW file. RAW makes color like clay, able to be molded into whatever form best conveys the desired subliminal message in the photo.
Film makers are masters at this. Last light I saw a mundane Prilosec (antacid) commerical on TV and was impressed with how the production designer or cinematographer had match the clothing and WB of the lighting in background to give everything a cool, moody, vibe; how you'd feel before taking it, then cut the after scene with warm colors and normal WB.
We need to look beyond the technical to see the broader perceptual goal - how we want the viewer to react. Being able to do that at will is a matter of knowing how to apply the technology effectively. In the case of shooting WB we simply need to keep the WB consistent shot-to-shot so it is possible to batch correct the WB in all the files the same way with a simple copy/paste of WB metadata in the RAW files. Trying to make it any more complicated isn't a bad thing if it makes one feel the color is "better", but is more work to achieve same end: color which fits the context of the message and looks real. That is a perceptual judgement that can only be made by eye
E-Vener wrote:
they don't use a colorimeter, they use a photospectrometer - -a much different and benerally more sensitive device.
Sorry..yes...colorimeter is for screen. Photospectrometer is for reading off a surface (basically has an LED light in it and a different sensor). But they do test each one and the material goes all the way through so no worries about it getting wet, etc...
kenyee wrote:
Sorry..yes...colorimeter is for screen. Photospectrometer is for reading off a surface (basically has an LED light in it and a different sensor). But they do test each one and the material goes all the way through so no worries about it getting wet, etc...
Actually, no...
A photospectrometer is capable of measuring the entire spectrum continuously.
The colorimeters used for color reproduction measure color in terms of RGB tri-stimulus values with narrow-pass filters.
Most camera manuals give you instructions on how to do a Custom White Balance. Most require that you take a shot of either a white paper (like ink jet paper) of a neutral gray card (like the Kodak 18% gray card). What you are telling the camera is that the white card is white and to make it white. The camera will apply the appropriate filtration to do so., Or the neutral gray card has no color tint (naturally depending on what the camera manufacturer recommends you to use) and the camera will make the gray image with co color cast. Just follow the directions in the camera manual. No need for fancy stuff.
In my opinion either of the methods mentioned above will work but with varying degrees of success. Yes a lot of publications and website advocate using a "white" piece of paper was a white balance target but most paper is not really white. Get a piece of paper from three different vendors and layer them on top of each other and see if you don't see some differences in color, at least that has been my experience. Also most gray cards were designed to do one thing reflect ~18% of the light that hits it. They are not always a neutral gray and can add a color shift. If you really want to be safe always shoot in RAW as this will allow you to tweak the WB in post processing. The white paper or gray card methods will get you kind of close and if that meets your needs than great but for consistent results every time I recommend a consistent WB tool.
