White is white. Or is it? We see a white colored shirt as white when the person wearing it stands under the sun or in the shade or even inside the house. We see it as a white shirt regardless of the weather outside or the time of the day. Our eyes are wonderful. They adapt to the ambient light colors. When it comes to photography, it takes a whole new dimension. The same white shirt looks bluish in shade or in cloudy weather. It looks yellow-orange when photographed inside the house when the room is lit by bulbs. The camera sensor or the film can not adjust automatically to the color change. The auto ambient light adjustment happens in post-processing stage even if you select it in the camera.
There are some terms and fundamentals that have to be understood first before going any further.
Color Temperature –
It has been described most simply as a method of describing the color characteristics of light, usually either warm (yellowish) or cool (bluish), and measuring it in degrees of Kelvin (°K). Color temperatures over 5000 K are called cool colors (bluish white), while lower color temperatures (2700 K – 3000 K) are called warm colors.
White Balance is another term that is commonly used to indicate color temperature settings in photography. Initially films used to be marked as ‘Daylight Balance’ or ‘Tungsten Balance’ or some other similar words. This indicated that the film when used under the indicated ‘balance’ gave the results similar to our perception. White shirt looked almost white when the correctly balanced film was used regardless of the lighting. There were color filters available to use the film in different ambient color (we should now comfortably be calling it as different color temperature). Sensors also capture the colors in the same way but thanks to digital processing in the camera, the white balance can be set so that the camera applies the color correction (or digital color filter) and achieves proper white balance. For those clicking raw, this setting proper white balance provides a good starting step in some of the post-processing softwares.
In-camera White Balance
The camera has some basic built in white balance settings. These are –
Auto – The camera calculates the white balance considering that every color in the frame will average out to white and the brightest point in the frame is pure white with no color cast. This works fine in most situations but is never truly accurate.
Daylight / Sunlight – When shooting directly under sunlight. This is what most film rolls were set to.
Cloudy & Shade – These are two more settings (sometimes subsettings of daylight) that have increasing degree of warm hue added to them.
Fluorescent – At the peak of industrialization this was the default light that was used in offices and various other organizations. The so called ‘tubelights’ and present day ‘cool light’ lamps have this color. Our eyes adapt to it but the camera sees things as greenish. Setting to this shade add a bit of magenta and red-yellow color.
Incandescent (or Tungsten) – This is for the old bulbs with their yellowish light. These lamps have mostly been phased out but since the light looks pleasing to the eyes, recent lighting solutions offer a slightly less yellow version of these marked as ‘warm white’. Setting the camera to this adds a blue filter to the image.
Advanced settings – Cameras also feature setting the Kelvin directly or sometimes taking reading from a white/grey surface and calculating the white balance from that.
For the best results, I still recommend clicking raw and adjusting the white balance while post-processing. (This is the reason why this topic listed under ‘Darkroom’).
Color Balance –
Quite frequently this is confused with the white balance explained above. The color balance goes beyond white balance. Color balance is a broad term. It includes color casts (apart from the simple warm-cool spectrum), changes in hue, color shifts, relative difference in colors and the white balance too. Color casts are commonly seen due to large reflective surfaces of different colors. Think of a picture of an individual in broad daylight, standing next to a green colored wall. The skin color will look greenish even though the white balance might be correct. All the colors may get shifted on the color wheel due to wrong camera settings or wrong calibration (hue changes). Sometimes the deepest color will appear correct and the lighter shade of the same color will also appear correct but the color which should be in the middle may either appear to dark or too light causing a relative shift in colors. All these have to be corrected for getting pleasing results.
Some of the per-requisites for all the above are –
- The computer monitor should be correctly calibrated. I use a Spyder system for calibrating the monitor.
- The images should be viewed at 100% zoom and also the whole picture at a go.
- The computer monitor should be on for at least 30 minutes.
- The color space used should be supported by the monitor.
- The person changing the above settings should also be in the room for at least 15 minutes for the eyes to get adjusted to the monitor colors and the ambient light.
- RAW files are better adjusted than JPGs.
- Learn to think in CMYK instead of RGB when working with skin tones.
(Sunset on the hills with fog setting in. Nikon Df with Zeiss 135mm, f/4, 1/800, ISO 100. An image where the fine act of balancing color is no longer significant)
My workflow starts with adjusting the Daylight Balance or Color Temperature. It is usually easier for me to work on my computer when I adjust the daylight balance in the camera itself correctly before shooting. This ensures a proper starting point for my adjustments. Apart from correcting the daylight balance correctly, a lot of psychological impact of colors also has to be considered. Yellowish colors give a warm feeling and for photographs showing interiors, families inside a house and even for portraits the warm colors help the viewers connect with the photographs emotionally. The bluish or cool colors are associated with aloofness, cleanliness, cold weather and open spaces. Winter landscapes, seascapes, clean work spaces (hospitals, clinics, offices), foggy weather looks good with cool colors. Daylight Balance therefore has to be adjusted keeping in mind the overall photograph too. All in all, it should contribute to the image.
After adjusting the color temperature, I move on to removing the color casts. Usually, I demarcate the area and work in layers removing the color casts. It is very easy to completely remove the color casts and sometimes this may make the photograph look too artificial. Some amount of color casts are expected. After correcting the colors, quite frequently I have to revisit the curves. If you are still not comfortable with the curves then adjust the shadow and highlight details along with contrast and brightness. It is very easy to overdo everything so always stop a little short of what you feel is right. Take a look again and then proceed further.
I do not use Auto Color Balance. The auto color balance is based on the surmise that in any scene, there is an equal distribution of colors and all the colors should therefore when mixed, balance out to a grey tone. Color labs from the film days also used to work on this. It was therefore not a wonder that most of the people turned out looking reddish when their photos taken in gardens with lots of greens, were printed. Auto Color Balance may give a good starting point but it is almost never correct. So stop depending on it solely if you were doing so. Going further, do not use the Auto Color Temperature setting on the cameras too.
It helps to understand the various icons used in cameras to represent daylight balance and to remember some of the common color temperatures. Memorize some of the commonly used Kelvins.
Since our eyes are most sensitive to problems in colors of skin tones, some more tips for portraits –
- Skins of babies look better when they are a little pinkish. Avoid cyan at all costs.
- A little bit of warm touch makes the skins of adults look better but excess of it can make them look sick.
- Use natural light whenever possible
- When in confusion, consider the face and expose accordingly.
- In cases of mixed skin tones, it helps to increase the shadow and highlight details. The light skin should not get blown out and the dark skin should not be underexposed.
- Darker skin tones have an increasing amount of cyan too apart from the regular mix of magenta and yellow. (Reducing the saturation further brings out the beautiful darkness of the skin tone)
There are a number of recommended formulas for reproducing skin tones accurately. Each image editor has its own recommended formula. These formulas are usually expressed as relative percentages of cyan, magenta, yellow and black (CMYK scale)
One such common formula for adult white skin – find the cyan value, magenta should be double that of cyan, and yellow should be around one-fifth to one-third higher than magenta (20c 40m 50y).
Skin tones vary widely among individuals. Therefore, the best any recommendation can give you is a starting place. Make your own formulas as per your image editor and taste.
(Girl holding a Color-Checker card.)
There are some easy alternate methods too but these are not always available and sometimes not too comfortable to use. One such aid which I recommend is the Color-Checker card. It is easily available in most photography shops and including a shot of it makes things easier. Some of the cameras have an option to set the Light Temperature using a simple but automated method. The camera is used to click a photograph of a true white or grey (I prefer the 18% grey card without any color casts) and then the exact Kelvin is automatically calculated and applied to the photos clicked there on.
If nothing else is available, use an object that is ‘pure white’, as a reference. It can be a sheet of paper, white teflon tape, white wall or maybe even the case of your new filter (I sometimes use the white plastic back of my filter cases). Anything works, as long as it is pure white. Grey is more helpful than white since it can also be used for setting proper exposure using a spot-meter or a center-weighted meter. However, when it comes to color balance, any shade/tint of grey or even white works, as long as they are free of any color casts. Matt finished items are easier to use than glossy items.
The balancing act becomes difficult in cases of mixed lighting. If using flash, gel filters can be used to blend with the lights or to be creative. In case of natural mixed light, there is little that can be done apart from corrections in post-processing.
Depending on your comfort level, use any of the methods I have outlined or anything that you are happy with but be open to experimentation.