White balance is often a misunderstood term for many new to photography. Have you ever taken a photograph with your camera white balance set to auto and for some strange and unknown reason the image had an unusual color cast? If so, the following explanation may help to clear the confusion.

When you manually set the white balance you are programming the digital camera with the color temperature of the light that is illuminating your subject. The temperature of this light is measured in degrees Kelvin.

Without going deep into physics, imagine for a moment a piece of metal heated by a very intense flame. As the metal becomes hotter and the temperature reaches a point where the metal begins to emit light, it will glow with a deep reddish color. As the temperature of the metal increases further the color will change to yellow and ultimately to blue. The hotter the metal becomes, the higher the degrees in Kelvin the color of the light.

These same temperatures and colors of the glowing metal are correlated to colors of light we are all familiar with. The yellow-white color of a common indoor tungsten light bulb is rated at around 3200 degrees Kelvin, bright mid-day white sunlight is rated at 5500 degrees Kelvin as well as most flash units. The color temperature at twilight can exceed 10,000 degrees Kelvin.

Visible Light Spectrum

White mid-day sunlight will shine roughly equally across all wavelengths of light in the visible spectrum. Tungsten light has a greater amount of red and yellow than the rest of the spectrum. Thus, if you took an image of an indoor scene illuminated by tungsten light with film balanced for mid-day sunlight, the scene would appear to have a yellowish cast. Shooting that same scene with tungsten balanced film would make the colors of the subject appear as they would under mid-day sunlight.

Do you remember taking images outdoors of people standing in full shade or under cloudy skies with daylight balanced film? There was that awful blue cast in the developed prints that usually spoiled the photographs. That was because the color temperature in those lighting conditions was somewhere between 6000 and 8000 degrees Kelvin. With slide film, a warming filter was usually used on the lens to compensate and with color film, adjustments had to be made in the filtration pack in the enlarger by a custom lab.

With digital cameras, getting accurate colors became much easier. The white balance can be easily dialed in before the shot is taken for a variety of lighting conditions and can be changed or finely adjusted after the image is taken if shooting in RAW format. On more sophisticated cameras one can set a custom white balance by shooting a white or gray card in the same light as your subject.

Subject Illuminated by Tungsten Lamp; 1st-5300K WB; 2nd-3300K WB; 3rd-Custom WB

So what exactly is happening when you set your white balance to the tungsten setting when your subject is illuminated by incandescent lighting? You are programming the camera to produce an image where your subject will have the color balance as if it was taken in lighting conditions similar to mid-day sunlight.

What do you do if you want to reproduce all those beautiful colors in a morning sunrise? You certainly wouldn’t want to set the white balance to the 3000-4000 degrees Kelvin to match the temperature of the light because if you did, the scene in the capture would more closely resemble what it would look like at mid-day. Shooting at the mid day sunlight setting of 5500 degrees Kelvin would give you all those warm colors usually associated with a sunrise though most likely a bit more exaggerated than what the eye perceived – the eye has a remarkable ability to adapt to changes in color temperature so white still looks “white” or at least close to it, in varying lighting conditions.

Street lamps and some fluorescent tubes introduce a problem when trying to get the colors of your image correct. These light sources don’t emit light across the entire visible spectrum so one can’t really set a white point. There will always be an unnatural color cast of some sort in the final image.

Mixed lighting poses another problem. As an example, in an indoor scene partially illuminated by tungsten light and partially illuminated by sunlight streaming in a window, one has to decide which temperature of light to balance for. There will always be a compromise as part of the scene will be correctly color balanced while the other part will have a color cast.

If you choose to use the auto white balance setting, the camera then has to “guess” at what the proper white balance should be for the light you are shooting in. Some cameras do this better than others though I advise that you not use the auto setting due to its inaccuracies.

So what’s my advice? I recommend that you keep your camera white balance setting at daylight for indoor shots with a flash and for most outdoor shots. If skies are overcast or if you are shooting in shade, use the overcast setting. If you require more flexibility or options you really should be shooting RAW format or if you want to make sure your subject has a color balance similar to what is produced by mid-day sunlight and have the camera option, take a custom white balance reading in the same light as your subject.

Step two in the Workflow Process (RAW Development)

In this article I’ll be offering a more detailed explanation of step two in the three step digital workflow process as described in my introductory post. Step two will be split into two parts while a third article will cover the last step. Once again, I cannot stress enough the importance of having a calibrated monitor when doing your own image enhancement and printing.

As I do most of my photography using an Olympus E-1 DSLR, my examples in this article will come from the use of Olympus Studio and Adobe Photoshop CS2 software. I don’t claim the camera and software I use are the best available or the best solution nor do I wish to take up argument with anyone with opposing views. The combination works for me and I only wish to share what I’ve learned with others so that they may be better educated to make their own decisions on what works for them.

I’ve always captured my camera images in RAW format, bypassing the in-camera processing and converted them to Tiffs in the RAW development process instead of capturing them as Jpegs. This allows for increased dynamic range (the range of light between absolute black and absolute white) and the option of making white balance, contrast, sharpness, saturation and small exposure corrections after the image is taken.

Think of shooting Jpegs as analogous to shooting slide film and shooting in RAW as equivalent to shooting negative film. One has to be very careful to expose correctly when shooting slides or Jpegs as WYSIWYG. Some adjustments can be made to Jpegs in post processing though this usually results in degradation of the image.

With RAW format as in negative film, many options remain open for adjustment after the image is captured, one important adjustment being white balance. The auto white balance setting in most digital cameras at best makes a fairly good approximation of the white point and often times a poor one resulting in an undesired color cast while a daylight or overcast white balance setting doesn’t work in all cases. Unwanted color casts in color negative film could be corrected before a print was made by adjusting color filters in the enlarger head.

Olympus Studio - Browse window

After I’ve downloaded my RAW image files from my camera to my computer via Olympus Studio, I am presented with the screen above. From here I can view the images in browse mode with the in-camera settings — contrast -2, sharpening 0, saturation at default, white balance at either 5300K (daylight) or 6000K (cloudy).

The left side of the screen offers a directory structure where my images are stored while the right side presents a histogram of the image highlighted and its general and Exif data. From this screen I can get a good idea of the images I’ll consider for printing or for use on the web. I can choose to mark those I’m interested in by clicking on the red box (or yellow or blue) in the frame of the image.

Olympus Studio - View window

If I wish to get a larger view of the images I can go to the “view” screen shown above. Here the directory structure on the left side is replaced with thumbnail images in the open directory and the center of the screen becomes the enlarged image of the highlighted thumbnail.

Olympus Studio - Light Box window

If I have two or more images of the same or similar composition I can go to “light box” mode where I can do a side by side comparison. This is great for determining which image is the sharpest or has the depth of field I prefer.

Olympus Studio - Image Editing window

Once I have an image I want to print, I open the image editing window from within Studio. The only reason for this is to arrive at a fine tuned white balance setting.

From this window I am able to open up the RAW converter (second window from left) and play with the white balance setting and tint to arrive at the overall coolness or warmth that I would like the image to have. This is done with the help of the information window (lower left window) which gives an RGB readout of the group of pixels that the cursor is suspended over in the image. This tool can give me a good indication of the color balance in the whites, grays and blacks in the image. For example, if you have equal values of red, green and blue in the grays, then you have a neutral gray. If you have more red then green and blue, you have a warm gray and if more blue than red and green you have a cold gray.

There are other image enhancement features available in Olympus Studio though I choose to do those enhancements within Photoshop CS2. Once I am satisfied with my white balance setting I note the changes made, close the image editing window without saving and open up the RAW development window shown below.

Olympus Studio - RAW Development window

There are four different RAW converters available within Olympus Studio though for most of my work, I use the “High Function” engine as the details in the highlights seem to be better than what the other three can produce. Another highly recommended engine is “Advanced High Speed.”

As you can see I settled on a white balance of 5900K which warmed the image slightly and I removed a slight magenta cast by choosing a -1 step in the tint setting (a minus step takes magenta out or adds green while a plus step adds magenta or takes away green). I increased the exposure slightly by .1EV, left the contrast, sharpness and saturation at their default settings (I handle these adjustments in Photoshop) and chose the Adobe RGB color space as it has a wider color gamut than sRGB.

There has been quite a bit of discussion on whether to choose sRGB or Adobe RGB as a color workspace within Photoshop. I settled on aRGB as my print more closely resembles what I see on my monitor using this color space. This probably has to do with the fact that high quality photo inkjet printers can produce a wider color gamut than sRGB. If you have a professional service handle your printing than I would recommend saving your images in sRGB as pro labs predominately use this color space.

I then save the image as a 16 bit Tiff file with no compression. This gives better image quality than a Jpeg and allows for repeated changes and saves from within Photoshop without loss of quality.

In the next article in the series, Digital Workflow Explained – Part 1B, I’ll write about my use of Photoshop CS2 for image enhancement.

My wife and I went for a hike at Bartholomew’s Cobble, a 329 acre preserve maintained by The Trustees of Reservations. All together we walked about 3 ½ miles of trials in this beautiful reservation that provides a major migratory and nesting area for over 250 species of birds.

Elizabeth Freeman

Bartholomew’s Cobble has an interesting history. Originally it was part of a 3000 acre farm owned by Colonel John Ashley back in 1735. In later years, Mr. Ashley, a prominent lawyer, had in his household a young slave woman by the name of Mumbet (Elizabeth Freeman). As Mr. Ashley’s home was the center of social and political life in southern Berkshire County, Mumbet overheard many talks about freedom, liberty and the Bill of Rights while attending to the family. According to family lore, one day after suffering physical abuse from Mrs. Ashley she decided to approach another prominent layer in the area, Theodore Sedgwick, and sue for her freedom. In August of 1781, Elizabeth Freeman won her freedom and became the first black slave to be set free in the United States. Her case was one of a series of cases in 1781 that eventually led to the abolition of slavery in Massachusetts.

Hurlburt Hill 1; © Copyright Reserved, Richard Lovison, 2008

The first part of our journey took us to the top of Hurlburt’s Hill at an elevation of 1050 feet. The above image is looking north toward the town of Sheffield. The field upon which we were sitting was beautiful and serene with a number of nesting boxes for birds along the path. It was quite peaceful to watch them fly above.

Hurlburt Hill 2; © Copyright Reserved, Richard Lovison, 2008

This second image was taken looking west.

Spero Trail 1; © Copyright Reserved, Richard Lovison, 2008

On our way down from Hurlburt’s Hill we took the Tulip Tree Trail that eventually led us to the Spero Trail. The latter looped around a freshwater marsh where the above image was taken.

Spero Trail 2; © Copyright Reserved, Richard Lovison, 2008

A bit further along we walked next to the Housatonic River and then along side a grove of young trees where this last image was taken.

It was a wondrous day and we both came away with our spirits uplifted. It truly was a great honor to walk the same land as Elizabeth Freeman, a person who possessed such courage, integrity and strength of spirit. My wife and I are thankful that this beautiful reservation is under the care of the Trustees for future generations to experience and we look forward to returning for another visit.

Before I write in detail of the second step in the digital workflow process I thought I’d write about what I feel are the two most important decisions to make when building a photographic computer workstation. These would be the choice of monitor and the process of calibrating it.

As LCD monitors have all but replaced the old CRT type, one has to be careful which LCD to purchase as there are a few different types of panel technology. The three main types are TN, VA and S-IPS. As I’m not a tech junkie, currently there may be other types available or variants of the ones I mentioned.

What is most important are the horizontal and vertical viewing angles as well as the color accuracy of the monitor. S-IPS panels are superior in both aspects being true 8 bit panels with great viewing angels while TN panels are the worst. The TN panels are only 6 bit and thus are not able to display 16.7 million colors without using a process called dithering, which has its drawbacks. LCDTech provides information on the type of panel that is in each major LCD monitor.

I purchased a highly rated TN panel (Samsung 226BW) as I was on a strict budget. The color quality never presented a problem though the extremely poor vertical viewing angle has. When working within Photoshop, I need to reduce the size of my image to fill a small section at the middle of the screen to get an accurate representation of brightness, contrast and color rendition across the entire image before my final save of the image file. There is just too much variance between contrast and brightness from the top of the screen to the bottom.

Are the vertical and horizontal viewing angles of my TN panel horrible? No. Do the poor viewing angles make my image processing difficult at times? Yes. Would I rather have an S-IPS panel? Yes.

So my advice is to do your research. Go online and gather information on the plus and minuses of the different panel technologies. And if you have the opportunity, go to a local computer store and view the different types of screens in person.

Once you purchase your monitor you will have another issue to deal with. If you think you will be able to match the image you see on your new LCD panel with its default color settings, with the print that emerges from your inkjet, you are mistaken. And if you think Adobe Gamma, the software provided with Photoshop, will calibrate your monitor to a useful state you are mistaken once again.

Nothing short of using a colorimeter will give you an accurate monitor profile so what you see on the screen is a close representation of what is printed. Color calibration is essential if you intend to shoot in RAW format and do your own image processing.

ColorVision Spyder 2

There are many different manufacturers of colorimeters, ColorVision being the least expensive. For under $70 one can purchase a Spyder 2 that will give results far superior to anything that can be obtained using Adobe Gamma. They work on both Macs and PCs and within a few minutes of hardware processing, will produce an accurate monitor profile.