Color is so much stranger than it seems at first glance. When we were children learning red, green, yellow, orange, blue...it seemed so straightforward. So easy to get the right answer. When did you realize that it was all a sham? An illusion? For me it happened in high school when I always wore socks to match my shirt (yea 80's!) I bought a pair of royal blue socks - perfect - until I got them home under the incandescent light. They were purple. What? Okay, then, fine. I'll wear them with my purple shirt - until - I got to school and they were blue again. How mortifying. What had happened?
Notice the cool blue color temperature in the middle of the bottom row.
In the previous post we looked at the color temperature, or color of the light. That actually has little to do with color rendering, which is the color of the objects under the light. See the difference? Either a warm source like incandescent or a cool source like daylight can render the color of objects nearly perfectly (my socks were blue under both.) It has to do with how much of the pigment is reflected back to your eye by the light source.
The three pictures above subtly illustrate differences in color rendering (or color accuracy) on the apple. The apple is the same, but it appears more pink, orange, or deep red under different lights. In the picture on the right the yellows in the apple are easier to see; In the middle picture, the dark lowlights are well defined; The one on the left seems smooth in color - neither the lowlights nor the yellows are obvious. It is important to know not only whether a source is warm or cool (color temperature) but also how it renders the objects under its light (color rendering.)
The new Lighting Facts Label (at left) required on light bulbs (lamps) sold in the US lists the color of the light, but not its color accuracy. Another new label (below) uses both. As a consumer of today's complex lighting sources, you need to know both. The color accuracy scale goes to 100. In most cases, choose the highest number you can afford. Something in the 80s for fluorescent and close to 90 for LED. If you have the opportunity to try multiple sources to see how they look in your final application, that is even better. Check color accuracy to avoid disappointment and purple...no, blue...no, purple socks - or worse!
Enacting a Metric
The International Association of Lighting Designers (IALD) is currently participating in the development of an international lighting certification. The debate that surrounds this whole idea is an interesting topic in and of itself. It stems from 2009 Legislation in Texas that would have required a license to practice lighting design. I recently sat in on an IALD webinar about credentialing, and while I am as credentialed up (kind of like tatted up, only I'm not that) as anyone I know, I'm not yet convinced that this is the answer.
That is a debate I would rather not enter, though!
What I want to share here are some great metrics that the group has thoughtfully accumulated to measure and provide the elusive definition of the profession of architectural lighting design. Currently they identify seven domains that define the core competencies that a lighting designer will be required to illustrate and maintain for certification. They are:
1. Goals and Outcomes - Project goals are met in the final lighting design.
2. Collaboration - The lighting designer collaborated with all members of the team throughout the duration of the project.
3. Ingenuity - The lighting designer proposed creative, ingenious solutions to the design of the project.
4. Synthesis - The lighting solutions are integrated and the lighting design complements the overall design solution of the project.
5. Science - The design illustrated proper application of technology and consideration of human psychology.
6. Stewardship - Avoid or minimize harm, discomfort, or waste.
7. Human Experience - The lighting design contributes to and enhances the human experience of the space.
I think this is a great list and something to consider every project. What do you think? Is anything missing? What would you add or delete from the list? The tougher question - are these measurable?
Lisa J. Reed, lighting designer and Principal at Envision Lighting Design, LLC