Tuesday, August 27, 2013

Anatomy of a "Hue Angles" column

This column marks the seven-year anniversary of Hue Angles. Perhaps it is time to review the premise of the column: what is and what is not a Hue Angles. The charter defines the column as “tidbits of interesting lore shared by ISCC members in short-essay form.” The task is harder than it looks, yet also intrinsically fun. Not only should there be a hint of color education, but some of the writer’s personal experience is an important ingredient. Terry Benzschawel’s color-science mind in the job of a Wall-Street quant was a great example. So was Hugh Fairman’s essay on Henry Hemmendinger and colored M.C. Escher prints. Of course, Ralph Stanziola’s personal journey in selling color-measurement instruments was such a piece. I could mention others---they’re in the archives.

We need more such essays. I’m sure many readers could craft a story or two, taking off from a meeting trip or a sales foray, or even a journey to an art museum. Please let me hear from you.

Now, having reviewed what is (in my opinion) a Hue Angles column, let me talk about what is not in the charter. I was given the helpful suggestion to write about the color of fireworks, based on my having seen three separate fireworks displays simultaneously from a small island off the coast of Cape Ann in Massachusetts. As a lead off base, the person who suggested this topic provided an essay from the Konica-Minolta website (http://sensing.konicaminolta.us/a-colorful-explosion/). Upon reading that essay, I found it said all I could ever think of saying about firework color---and much that I had not known. Sparks cast by strontium salts produce red, sodium produces yellow (in moderation, please), barium produces green, and copper produces blue. Predictably, a mixture of strontium and copper produces purple. Although fireworks have been around for thousands of years, the use of metal salts to control color dates only from the 1830s. What was missing from this piece was another sort of spark---that of originality and personal investment. This essay was already written, and not a Hue Angles waiting to be born. It might be part of someone else’s testimonial, but not of mine.

So that is why I need your inputs.

Well, there is one twist to the firework story. Ever notice that firework displays that are shown in movies tend to be all washed out in color? In great part that is because the points of light saturate the photographic medium in all three channels. I wonder why movie makers aren’t more attentive to this problem. Maybe they want the dark parts of the image to show up, and are willing to sacrifice the firework display. But many people ignore such effects, which is why color management has a way to go before it is used widely and enthusiastically. John McCann could probably write a great Hue Angles on his experience with such effects and how they are remedied by high-dynamic-range images. He literally wrote the book on HDR [1].

Many of you have effectively written the book on other corners of our world. Let’s explore those corners together in the next seven years.

1. J. J McCann and A. Rizzi, The Art and Science of HDR Imaging. Wiley, 2011.

Michael H. Brill