Archive for September, 2011

Have you every had a photograph come out with a blue tinge and not know why? Have you ever taken a photo of a sunset and wondered why the brilliant reds and oranges didn’t show up on your image? It all has to do with white balance and color temperature, a topic that can be a little confusing. Having a basic understanding, however, opens up new and intriguing possibilities, particularly for Schutzhund photographers who shoot in a wide variety of lighting conditions.

One of the best explanations of color temperature comes from the Blue Crane Digital DVD, Introduction to the Canon 7D, Volume 1: Basic Controls, and is a primary source for the information for this post.

Color temperature measures the visible light spectrum. In the late 1800s, British physicist William Kelvin heated a block of carbon and observed that as the carbon got hotter, it glowed with range of different colors. At lower temperatures, it produced a dim red light. As the block continued to heat up, it progressed through the visible light spectrum to a bright blue-white at the highest temperature. This is where the term “white hot” has it origins.

The temperature value assigned to each color is in degrees Kelvin, a variation on degrees Centigrade. This value refers to the temperature at which the color was observed not the actual temperature of the heated carbon. Reds are at the cooler end of the light spectrum and blues at the hotter end. This is a little counter intuitive, as we tend to think of red being hotter than blue.

A very helpful chart is posted on Jeremy Birn’s website. I urge you to take a look at it. Jeremy is the technical director at Pixar Animation Studios and the author of the book Digital Lighting & Rendering. His explanation of color temperature is also very good and was a key source for this post.

Another key concept for photographers is the light spectrum is made up of electromagnetic radiation at various wavelengths, some of which are visible and some of which are not. The visible colors from shortest to longest wavelengths are violet, blue, green, yellow, orange and red. White light is a mixture of the colors of the visible spectrum, and black is a total absence of light.

So, at midday with a bright sun and no clouds, all the colors in the light spectrum are visible and shinning on your subject – the equivalent of white light or white-hot. No wonder colors can seem very faded, black or dark sable dogs look like blobs, and highlights blow out. Early morning or late evening, the hour before sunrise / sunset, is often referred to as the “golden hour.” At these times of the day, red or orange colors are present, because the wavelengths associated with them are less efficiently scattered by the atmosphere than the shorter wavelength colors, such as blue and purple. This creates the warmer golden hues and tones. For more information, see the NASA article “What Wavelength Goes With a Color?”  On cloudy days, yellow, orange and red wavelengths are filtered out, leaving the wavelengths towards the blue and violet end of the light spectrum. As a result, the light is more even and diffuse.

Many DSLR cameras come with the ability to adjust white balance settings. Featured settings include Auto White Balance, Daylight (sunny), Shade and Clouds for outdoor lighting, and Tungsten and White Fluorescent for indoor lighting. With each of these settings, the camera sets the white balance for specific Kelvin values to compensate for a particular lighting condition. In the more advanced cameras, photographers can set the white balance by Kelvin temperature values or by using a white balance card and the Custom setting.

Canon has an excellent explanation of white balance settings and examples of the effect different settings have on an image. Canon’s article may be viewed here.

The following summary for outdoor lighting white balance settings is adapted from this article:

  • Auto White Balance (AWB): Works best if the ambient light color temperature is between 3,000 K to 7,000 K. If there is no obvious white point from which the camera can evaluate the scene, there may be a colorcast or tint to the image.
  • Daylight:  Works best in bright sunshine. It will balance for a color temperature of around 5,200 K, which is actually very slightly cooler than noon sunlight.
  • Shade: These areas have a higher color temperature than sunnier areas, usually around 7,000 K.  Recall that blue has a higher Kelvin temperature value than red. This is the best setting for areas of light shade rather than very heavy shadow.
  • Clouds or Haze: This setting sets a color temperature of around 6,000K. It is best used on days when the sun is behind the clouds, creating very even and diffuse light.

For more about indoor lighting and how to use a white balance card to set a custom white balance setting, see the Canon article referenced above. I have a white balance card, but in the course of an ordinary Schutzhund day, the lighting can change so rapidly that I think it is more efficient to use the camera-supplied settings.

As a test, I took photos looking into our pool area (see images below), using the following white balance settings on my camera (Canon 7D): Auto White Balance, Daylight, Shade, Clouds, Tungsten and White Fluorescent. Notice how the appearance of the image changes. The Auto White Balance image produces the true to life colors for the day’s conditions; sun going in and out of clouds and my standing in an area where the sunlight is filtered through a few tree branches. The Daylight setting added in a bit of yellow, which may be compensating for my standing in a shadier area. Shade has more blues, so the Shade setting compensates by shifting the colors back to red, which in this case appears more yellow. The Cloud setting is still yellower than I’d like, but it is closer to the correct white balance than the Shade setting. Tungsten added a lot of blue, and White Fluorescent added a magenta or red tint.

On a whim, I took a few sunset pictures the other night. The focus is not good (handheld), but I wanted to see the effect of adjusting the white balance on the sunset. You can see in the images below that the Daylight setting produced the most vibrant colors. The Auto White Balance filtered the reds and oranges out, as this setting seeks to strike an even balance between all the color temperatures.

The advantages of having a correct white balance include saving post processing time and preserving data that would be lost if the white balance is adjusted in editing software, not to mention the obvious advantage of capturing realistic colors. By being aware of the Kelvin values, you also can use these settings to achieve interesting effects, such as adding, in essence, a color filter to the image. If you have never tried the White Balance settings in your camera, give it a try and let me know what you think.

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As I’ve been teasing the past few weeks on Facebook and Twitter, I am pleased to announce the launch of BJ Spanos Ink Photography, featuring:

  • Dog Sports – Photographing Dogs in Action – Playing, Competing, Training
  • Smug Mutts – Creating Memorable Photos and Artwork of Your Pet at Reasonable Prices
  • Fine Art – Photographs, Collages, Custom Photo Editing, Hand-Made Cards and Books

The website is also accessible via bjspanos.com.  Please stop by when you get a moment. It is definitely a work in progress, but I am open for business. If you are in the Atlanta area, give me a call. I would very pleased to work with you.  Also, I am happy to travel to photograph pets and/or working dogs and their handlers one-on-one or at trials, although I am not available as an event photographer.

Which brings me to some changes on the BJ Spanos Ink website. I also am pleased to announce that the Sport of Schutzhund: A Photographic Essay book is nearly SOLD OUT. I have a few more cases left (less than 10), but since the stock is almost gone, I have removed the Art of Schutzhund Photography section from the BJ Spanos Ink website. That part of the site now features BJ Spanos Ink Photography, as noted above. You can still order single copies from Amazon or from Leerburg. The special offer for a box of books for working dogs and Schutzhund clubs is still open as long as supplies last. The gallery of Schutzhund photographs that once resided on the Art of Schutzhund Photography site has been retired. Thank you to the photographers who graciously allowed me to include their pictures in this gallery. I will be posting a collection of my own Schutzhund pictures on the BJ Spanos Ink Photography site, as time permits.

Please be assured that my dedication to the Art of Schutzhund Photography remains as strong as ever. And, I fully intend to pen more posts to this blog on what hopefully will be a more regular basis. Thank you for your encouragement and visits. May this fall bring us all opportunities to grab some great shots of the dogs we love and admire!

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Hello!  It has been a very busy August and early September. As a result, I have had precious little time to blog. I hope to have some new posts up soon. One of the projects that has kept me busy is BJ Spanos Ink Photography, which will officially launch next weekend. I’ll have more to say about it then. . I am looking forward to cooler fall temps and colors, which always make for wonderful photo backdrops. Until next time, thank you for patience and understanding as I work through this hectic period – and thank you for visiting!

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