Episode 25: target temperature massachusetts gray

All Things Photography

We're at the magical tenth-of-a-quarter-of-a-thousandth episode, yet it doesn't feel like an episode over 24. Such is the magic of the internet and cold-brewed coffee made at home…

Speaking not-at-all about home or coffee, I've ground up an amalgam of color temperature and white balance topics, so let's brew things up!

The Color of Temperature

Heat a golf ball and it melts. Heat a theoretical black sphere that absorbs all light striking it and, eventually, it starts emitting its own light. Such an object — and it need have no particular shape, but a sphere is easier to imagine than a twisted dodecahedron with wings — is called a black body and with increasing heat the color of the light it emits rises from dim red to brilliant blue. That is the realm of color temperature.

Color temperatures that are visible begin around 800 degrees Kelvin and, well, I don't know if there is a limit to how high they go, but the charts I've seen top out at 12,000. Eight-hundred is that dim red, 12,000 is the brilliant blue. In between were orange, yellow, white, then blue, each color blending into the next.

Here's why hot is cool and cool is hot. A thousand degrees Kelvin is a lot cooler than 12,000, though red is considered a "hot" color, while blue is not. Graph courtesy of Bhutajata via Wikimedia.

And there's the challenge for most of us: the colors we consider warm, like red and orange, are very cool in the scheme of color temperature. And cool colors, like white and especially blue, are very hot as color temperatures. See below for comparisons of how the camera interprets colors based on what it thinks of reality.

Science is a cruel mistress, eh? But she's also the law of the land, so get used to it, mister!

I came up with a pair of images, imaginary images, that might help us keep in mind the contrariness of the color temperature scale, as compared to our everyday experiences scale: the beautiful blue sky is high above our head, and its color temperature is way up there too — 12,000 degrees Kelvin. The lava pool in our backyard is below our feet (not directly, and there's definitely no diving allowed) and its color temperature is way low — 1,000 degrees. Sky high. Lava low.

Learn it. Live it. Order pizza on two-for-Tuesdays. Good advice all around.

The Neutrality Tool

Light sources, from glowing black bodies to flashing liquor store neon to a flashlight being shined in your eyes, from candles to LEDs to fireworks, emit a range of colors that affect how our eyes perceive the color of the things those lights shine on. Our brains do a pretty good job, most of the time, in accounting for the color of the light as we interpret the scene. We know a yellow light bulb makes white things look yellow, so our brains adjust accordingly. Photographic media? Not so much.

Back in the days of color film, photographing indoors under regular light bulbs, using film that expected you to be outdoors under the sun and sky, would result in whites appearing yellow. Every color would be shifted toward yellow. If the color film was used to make prints, the yellowness could to varying degrees be corrected. If you were shooting slide film (also called transparencies), you were stuck with the yellowing.

The solutions were along the lines of: use the correct film for the lighting conditions (films were made for indoor and outdoor lighting); use a filter over the artificial light to have it match the expectations of the film; use a filter in front of the lens to do the same; fix it in printing. The goal in all of these is what is called "white balance" — getting the whites to look white and, thus, everything else should be accurate too.

With digital cameras, they can be adjusted to account for the color of the light source, often being set to do so automatically. Sometimes that works just fine, other times it misses the mark and, depending on the intended use of the photographs, that might not be acceptable. Even the presets for sunlight, shade, fluorescents, etc., are only approximations. Better than nothing, but seldom ideal.

For those needing or wanting color accuracy in their work, the Photovision One Shot Digital Target is a handy and versatile tool.

It is a spring-foldable square with a soft silver reflector on one side and three strips of neutral fabric on the other — black, gray, white. You can photograph this side and, thus, set the exact white balance for the current lighting conditions. Then, bang! Use that custom white balance to get color-accurate images.

Not only do you see the Digital Target, but you see the target photographed in open shade with the white balance on the camera set as indicated in each image — except for the center image, which was the same as the "Automatic" setting in the upper left, but neutralized in Photoshop by sampling the central, gray, panel of the target. Photoshop then adjusted all the colors to make the sampled one neutral. As you can see, the "Shade 8000K" version, below center, was pretty close, which makes sense since that was the lighting condition.

I tried out the 14-inch version, which folds down to 6 inches and slips into the included belt-mountable pouch. There are also 6-inch and 24-inch versions, and each comes with a DVD of instructive videos that are so easy to follow, hosted by a professional photographer with an easy manner, that it almost makes this product a great set of videos with a bonus reflector!

My example came from Tempe Camera, in Tempe, Arizona (www.tempecamera.biz) and perhaps available at your own local camera store, You can also find them at B&H and Adorama. The 6-inch lists for $30, the 14-inch for $40, the 24-inch for $69.

Tipping the Balance

Just as we use the white balance tools in our cameras and computers to attempt accuracy, we can also turn these tools against accuracy in a quest for, at least, a better understanding of the choices those tools are making and, possibly, some surprisingly interesting and good images.

The simple suggestion is this: change the setting on your camera away from automatic white balance and, instead, choose one or more that you know to be "wrong" for the conditions. Choose "daylight" (or whatever they call sunlight) when you're in a restaurant, "fluorescent" when you're in the shade, "overcast" when you're huddled around a bonfire at the beach. Or cycle between all the choices no matter where you are. What's the worst that can happen? You have digits to dispose of. But you might just find some keepers…

That spray of nine images, above, shows one set of results. Here, below, is another. Whereas the upper selections were shot in open shade, meaning the light source was mostly a big blue sky (and light reflected from the wall of my house which, admittedly would have added some warmth to the light), these shots of the cactus are obviously in direct sunlight. The results, above and below, are a function of the camera taking your word for the color temperature and adjusting its color response to bring the colors back to natural.

Six images made with the indicated color temperature setting in the camera.

The camera adjusts its color response based on what you tell it in the setting for color temperature. By outright lying to the camera, it has no choice but to misrepresent the reality — garbage in, garbage out, as the saying goes. Or, perhaps in these or your own work, garbage in, art out. Maybe you want the scene warmer than reality? Or cooler? Or you want the colors to just be weird? Do what you want! It's photography, not a deposition!

When a Knack Becomes a Love

Maureen Grandmont spent decades teaching and, now retired with time on her hands and splitting her life between Cape Cod and Arizona, she has found herself more and more immersed in the pursuit of photography. Her early successes gave her confidence to keep working at it and she certainly shows not just enthusiasm, but also promise.

Listen in on our conversation touches on life and photography and a few other things, but I'll let her photography do most of the talking.

The artist as a tourist in Tuscany: Maureen Grandmont. Photo by Richard Grandmont.

That's What She Said

Libba Bray is an author of Young Adult Fiction Margo Georgiadis is the CEO of Mattel. Ellen DeGeneres is a comic and talk show host. What do these three have in common? They were chosen for their quotes on balance. Ms. Bray's is the longest, so I'll print it here, and you can listen to my dulcet tones reciting each quote in the show.

“In each of us lie good and bad, light and dark, art and pain, choice and regret, cruelty and sacrifice. We’re each of us our own chiaroscuro, our own bit of illusion fighting to emerge into something solid, something real. We’ve got to forgive ourselves that. I must remember to forgive myself. Because there is a lot of grey to work with. No one can live in the light all the time.” — Libba Bray

You can learn more about Ms. Bray, and see her writings, at libbabray.com.

And That's All He Said

Cut! That's a wrap! (Bet you didn't know I know filmmaking lingo, huh? Watch this: Haul that 10k up, light the rack, check the gate and shiver me timbers! Gives you goosebumps does't it? Or the yaws…)

But that does end this episode of All Things Photography; I hope you enjoyed it and found it useful.

Oh, postscript: I did respond to a question from an audience member, asking for my opinion of this painting by Kazimir Malevich, "White on White." I give my thoughts in the audio, and share the image here for your own viewing and, hopefully, commenting.

White on White, oil on canvas, 1918 by Kazimir Malevich.