What Color is My City?

The city of Los Angeles is converting its streetlights from orange-gold sodium vapor technology to cold, white light-emitting diodes. It’s a transition that will change the color of the city at night, in a place with a long history of experimentation with artificial lighting technology. That means not only that the city will appear different, but it will no longer correspond to memories of its coloration, or to its depictions in famous films.

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ARE THE DEMANDS IN ENTERTAINMENT LIGHTING TOO HIGH FOR WHITE LIGHT EMITTING DIODES?

10.25039/x48.2021.po04 ◽

2021 ◽

Author(s):

M. Nilsson Tengelin ◽

N. Mylly ◽

P.O. Hedekvist

Keyword(s):

White Light ◽

Light Quality ◽

Lighting Design ◽

Data Sheet ◽

Proper Function ◽

Light Emitting ◽

Lighting Technology ◽

Lighting Systems ◽

White Light Emitting Diodes

This paper reports the result of a survey on entertainment lighting distributed to 246 museums and 56 theatres in Sweden. The questions concerned the lighting technology used, experience from changing lighting systems, plans, problems, apprehensions and expectations. The replies showed that the transition to LED has been much faster in museums than in theaters and 35% of the theatres do not plan for a transition to LED. Reasons given are economy, light quality, and dimming functionality. Lighting professionals are generally sceptical in exchanging halogen lights. The artistic expression in lighting design goes beyond the specifications and what is promised in the data sheet. To facilitate a smoother transition to modern lighting technologies, the quality of the white light and proper function of the luminaires must be ensured and the communication between the manufacturers, retailers, lighting professionals and other artistic functions must be improved.

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Design of highly efficient phosphor-converted white light-emitting diodes with color rendering indices (R1 − R15) ≥ 95 for artificial lighting

Scientific Reports ◽

10.1038/s41598-019-53269-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 11

Author(s):

Yong Nam Ahn ◽

Kyu Do Kim ◽

Gopinathan Anoop ◽

Gab Soo Kim ◽

Jae Soo Yoo

Keyword(s):

Light Source ◽

White Light ◽

Light Emitting Diodes ◽

Light Sources ◽

High Definition ◽

Light Emitting ◽

Artificial Lighting ◽

Red Phosphors ◽

White Light Emitting Diodes ◽

Color Rendering

AbstractPhosphor-converted white light-emitting diodes (pc-WLEDs) are excellent energy-efficient light sources for artificial lighting applications. One goal of artificial lighting is to make objects/images look natural – as they look under the sunlight. The ability of a light source to accurately render the natural color of an object is gauged by the parameter – color rendering index (CRI). A conventional pc-WLED has an average CRI ~ 80, which is very low for accurate color reproduction. To utilize the pc-WLEDs for artificial lighting applications, all the CRI points (R1 – R15) should be above 95. However, there is a trade-off between CRI and luminous efficacy (LER), and it is challenging to increase both CRI and LER. Herein we propose a novel LED package (PKG) design to achieve CRI points ≥95 and efficiency ~100 lm/W by introducing two blue LEDs and a UV LED in combination with green and red phosphors. The silicone encapsulant, the current through the LEDs, and the green/red phosphor ratio were optimized for achieving high CRI and LER. Our re-designed LED PKG will find applications in stadium lighting as well as for ultra-high-definition television production where high CRI points are required for the artificial light source.

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Review: Urban Latino Cultures: La Vida Latina en LA by Gustavo Leclerc, Raúl Villa, and Michael J. Dear (eds.)

Ethnic Studies Review ◽

10.1525/esr.1999.22.1.126 ◽

1999 ◽

Vol 22 (1) ◽

pp. 126-128

Author(s):

Catherine S. Ramirez

Keyword(s):

Twentieth Century ◽

Los Angeles ◽

Mexican American ◽

History Of ◽

Crime Wave ◽

Eighteenth And Nineteenth Centuries ◽

The City ◽

History Of Los Angeles

Throughout the twentieth century (and now the twenty-first), the specter of a Latina/o past, present, and future has haunted the myth of Los Angeles as a sunny, bucolic paradise. At the same time it has loomed behind narratives of the city as a dystopic, urban nightmare. In the 1940s Carey McWilliams pointed to the fabrication of a “Spanish fantasy heritage” that made Los Angeles the bygone home of fair señoritas, genteel caballeros and benevolent mission padres. Meanwhile, the dominant Angeleno press invented a “zoot” (read Mexican-American) crime wave. Unlike the aristocratic, European Californias/os of lore, the Mexican/American “gangsters” of the 1940s were described as racial mongrels. What's more, the newspapers explicitly identified them as the sons and daughters of immigrants-thus eliding any link they may have had to the Californias/os of the eighteenth and nineteenth centuries or to the history of Los Angeles in general.

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