rosenfeld art sandiego2011

LIGHTING ART WITH LEDsat the

The Smithsonian American Art Museum

SCOTT ROSENFELD L.C., IESNA

The Smithsonian American Art Museum and The National Portrait Gallery were recently renovated and enhanced. The building was commissioned by President Andrew Jackson as the US Patent Office and dubbed a “Temple of Invention” upon it 's completion to signify it's resemblance to the Parthenon and it‘s role in spurring industrial innovation. Smithsonian's renovation included new lighting systems for 150,000 square-feet of exhibit space, plus a new 23,000 square-foot covered courtyard designed by Norman Foster. The Old Patent Office predates both artificial lighting systems and photography.

This is a patent with an image of the Old Patent Office in the background, it was issued to a Thomas A. Edison for improvements to the telephone. It is interesting to note that when this patent was issued in 1882 while the museum was in the midst of an eight year period of renovation. Smithsonian’s recent renovation of the building is only one in a long history where lighting designers, architects and engineers have been challenged with how to best bring light into this grand old building.

Controllable Qualities of Light

1. Angle2. Intensity3. Distribution4. Color5. Movement

Breaking down light in this way come out of tradition established in theatrical lighting. Museum, like the theater, primarily use focused lighting so for I like using these five properties as an organizing structure to discuss lighting design.

Grand Salon of the Renwick Gallery is 10.5 meters tall. This room is currently lit with conventional PAR38 and PAR46 incandescent lighting. As of February 2011, I have not found SSL retrofit products that can replace the existing 250 watt incandescent spot and flood lamps.

Typical Museum Lighting Requirements

1) Most Sensitive: 50 Lux2) Moderately Sensitive: 200 Lux3) Non Sensitive: No limit

• Intensity in museums is driven by conservation for the artifact. Use only the smallest quantity of light necessary to experience what is relevant about the object. “Make every photon count”.

• All light is damaging, requirements are based on smallest quantities of light needed to see. • Light is defined as wavelengths between 400 and 700nm. Other optical energies (IR and

UV) need to be minimized or eliminated, but minimizing the quantity and duration of illuminance (light) is essential for the preservation of organic colors.

Smithsonian American Art Museum’s 19th Century Gallery. Illuminated with Incandescent lamps.

Smithsonian American Art Museum’s, Luce Center. Illuminated with incandescent fixtures. Future site of a Gateway demonstration project.

Smithsonian American Art Museum’s, Luce Center. Illuminated with incandescent fixtures. Future site of a Gateway demonstration project. 2.5 meters



Finding SSL retrofit lamps with the correct beam distribution for museum applications is an extreme challenge. For American Art’s Gateway project we found only a single manufacture making wide floods lamps (52 degree) and very narrow beam lamps (~4 degree). Neither the 52-degree of the 4-degree lamps match the intensity of the incandescent (halogen) counterparts. I am aware of no manufacture making lamps with asymmetric distribution for wall washing.

Smithsonian American Art Museum’s, Luce Center. This is an odd case where I am wall washing with a round lamp distribution, note the three scallops above each case. These cases are illuminated with three 50 watt MR-16 incandescent (halogen) lamps with prismatic lenses. The proposed Gateway demonstration project will replace these lamps with four 7-watt/ 52 degree MR16 LED retrofit lamps.

MR-16 OBJECT LIGHT MR-16 WALL WASHER

THREE CHOICES OF LENSES TO SHAPE THE LIGHT BEAMMR-16

Custom MR16 lighting fixtures for the Luce Center. The MR16 is a very glary source of light and great care was taken to reduce this glare by using a deep matte black snoot on the object light and a brushed aluminum kicker with a matte black edge on the wall washer. Manufactured by Zumbtobel Staff.

PAR-30 WALL WASHER

LENS

LIGHT REDUCTION SCREEN

OPTIONAL KICKER REFLECTORBLACK CUT-OFF

Unique properties of the wall washer developed for this project include a removable kicker reflector and a black interior for the wall washer.

3 TYPES OF LENS 70 Degree 55 Degree 55 X 75 Degree

PAR-30 OBJECT LIGHT

CUT-OFF AND CROSS BAFFLE

ON/ OFF SWITCH

Three different asymmetric lenses were developed for the project. Asymmetrical light distribution is essential for good wall washing that provides for an even light that subtly gets dimmer toward the ceiling without scalloping.

Smithsonian American Art Museum. Lighting and photography by Scott Rosenfeld

Rose Gallery at the Smithsonian American Art Museum. Future site of a Gateway Demonstration Project. Most of this room is illuminated with incandescent, the end wall is lit with LED’s.


This wall is illuminated with LED retrofit lamps. The wall to the right is illuminated with standard PAR30 and PAR36 incandescent lamps. The lighting technique used to light most painting galleries at American Art is separate system for wall washing and spotlighting.


LED Wall Wash Only with spread lenses. This slide shows the spotlighting turned off, what remains are three PAR30/ 20watt/ 25 degree LED Wall Wash fixtures with spread lenses. The asymmetric spread lenses are essential for rendering the walls evenly so the light is brightest at eye level and subtly falls off toward the ceiling. Only 30-50 lux is required for this layer of light.


Wall wash with spread lens removed. The asymetric lenses are essential for counteracting the natural scallop of a light beam with a round distribution. The lenses produce a tremendous loss in luminaire efficacy – my dream is that an SSL manufacture could produce an asymetric array for wall grazing so I can stop throwing away so much light inside a glass lens.


Spotlights on and Wall washers off. Spotlights from right to left are 20 watt/12 degree/ PAR30L,. 20 degree/ 20 watt/ PAR30L, and 5 degree/4 watt/ MR-16.


Spotlights turned back on along with wall wash. The artwork is illuminated at 150-200 lux.

MR-16 retrofit lamp with diffusion lenses removed.

Lenses that fit into MR-16

Linear spread #1 on MR-16

Linear spread #2 from MR-16



In addition to asymetric low-glare flood lighting, museums also require precise spotlighting with a variety of beamspreads. The lamps we are considering for our Gateway demonstration project include a 6-degree, a 12-degree and and 25-degree.

A common exhibit lighting technique is to match the size of the light to the size of the artwork. Framing projectors would seem to be the obvious tool, but the incandescent versions are inefficient and the only SSL product I’m aware of (winter 2011) is prohibitively expensive for general use.

PAR Lamps• Filament is located at the focus point.

• Lowering the voltage decreases size of filament.

• The ratio between the size of filament and the size of the reflectordetermines the size of the resultant beam of light.

Most spotlights rely on the physical properties of a parabola to produce a precise beam of light.

PAR-36 OBJECT LIGHT

12V/OFF/5.5V SWITCH

PAR36 LAMP WITH FILAMENT SHIELD

LAMP SNAPS INTO BACK OF CROSS BAFFLE. ASSEMBLEY ALLOWS EXTERIOR LAMP ROTATION AFTER CARTIDGE IS INSTALLED IN CANISTER

DUAL TAP 12V/5.5V TRANSFORMER

The museum worked with fixture manufacture Zumbtobel Staff to develop a new line of track lighting fixtures. This series consists of a family of three lights; a PAR36 object light (shown above), a PAR30 object light, and a PAR30 wall washer.

AR111- 4 DEGREE 12 VOLT

5.5 VOLT – PAR-36 PIN SPOT.

MR-16 --15 DEGREE (ESX ) 12 VOLT

Common incandescent display lamps.

5.5 VOLT – PAR-36 PIN SPOT.

SSL MR-16

Flight of Europa, 1925 by Paul Manship


This sculpture is illuminated by four PAR36 fixtures containing 5.5 volt incandescent lamps. Photograph by Scott Rosenfeld



The photograph shows a single 5.5 volt incandescent lamp pushed to the left of the sculpture.



Final incandescent lighting.

Long view of gallery with incandescent lighitng. If the museum had used less precise light beams the small splashes of light and shadow behind each object would have been prominent and upstaged the artwork.

Renovated Gallery with incandescent low glare fixtures

Image of gallery circa 1999 before renovation. Note single row track with glary fixtures produces shadows on artwork.


Another example of the same phenomena. The lens and lamps were flush with the front of the lighting track fixtures from the 1960’s


The same hallway with the addition of incandescent wall washer lighting fixtures that shield the light from the viewer.

National Portrait Gallery. Lighting by Alexander Cooper, photography by Scott Rosenfeld

While most 20th century artwork needs to be flatly illuminated, 19th century artwork allows for more chiraschiro. For example in the image of Abraham Lincoln above the painting is illuminated at 15 footcandles with two incandescentPAR36 lighting fixtures and the background is illuminated at 5 footcandles with incandescent PAR30 floodlights. Lighting Design by Alexander Cooper, photography by Scott Rosenfeld

National Portrait Gallery. Lighting by Alexander Cooper, Photography by Scott Rosenfeld

Lincoln with PAR36 fixture turned off. Lighting Design by Alexander Cooper, photography by Scott Rosenfeld


Both PAR36 fixtures turned off. Lighting Design by Alexander Cooper, photography by Scott Rosenfeld


PAR36 fixtures aimed to the side.


Larger paintings don’t necessarily require more lighting fixtures. This portrait of Abraham Lincoln is illuminated with a two PAR30 spotlights and two PAR30 floodlights to illuminate the wall. Our goal is to match the size of the lighting beam to the artwork and avoid excess spotlight spill around the painting. Lighting Design by Alexander Cooper, photography by Scott Rosenfeld


Abraham Lincoln with flood lighting only. Lighting Design by Alexander Cooper, photography by Scott Rosenfeld


Larger paintings don’t necessarily require more lighting fixtures. This portrait of Abraham Lincoln is illuminated with a two PAR30 spotlights and two PAR30 floodlights to illuminate the wall. Our goal is to match the size of the lighting beam to the artwork and avoid excess spotlight spill around the painting.


Here are slides for after your talk about “intensity” to support the need to have the proper intensity in order for artwork to be experienced. Paul Reed and Thomas Dowling

Painting by Paul Reed. Without good R9 color rendering properties, we won’t simply can’t see red for all it’s worth.

X-rite color checkers are extremely useful target for museums to compare different color lamps. CRI, CQS, CCT along with it’s DUV are all useful color metrics, but there is no replacement for actually seeing the lamp at work.

Each of these LED MR-16 lamps are a slightly different color.


Gallery at 3000K


Gallery at 2800K

Sylvania’s flicker checker, developed to check for magnetic florescent ballast, is an extremely simple and useful too to… check for flicker.

MR-16’s often flicker, especially when installed in an electronic transformer (even at full voltage). Here, I retrofit the MR-16 into an AR-111 lamp and installed it in a magnetic transformer.

Questions1) Will the new lamps all be the same color?2) How will the heat from my sealed fixtures effect the SSL retrofit lamps?3) Will the color of the lamps remain constant over time?4) Will the lamps maintain their illuminance?5) Will lamps last their predicted lifetime?

rosenfeld art sandiego2011

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