In Manhattan, a custom solar telescope on the roof tracks the sun and beams daylight through a series of mirrors to light a 240 foot fiber optic sculpture that enlivens a major staircase in a large office building. The luminous sculpture provides a connection to the sky for those deep in the enclosed stairwell. Both sunlight and a connection to changing sky conditions are present as the sculpture continually varies in brightness and color, giving cues about clear or cloudy skies and also the time of day. A real time optical solar image of the sun is projected on the ceiling allowing the viewer the unusual opportunity to look into the sun.
光炮是一个定制的光学机器，安装在一栋 16 层建筑的屋顶上，通过两个轴的运动跟踪太阳。前窗由悬浮硼硅玻璃制成，可以过滤掉红外线和紫外线波长。大炮内部的镜面可收集、聚焦和重新定向可见太阳辐射，并通过下方的竖井进入重新定向光学装置。大炮的形状是为减少仪器的风阻而设计的。在风力较大的情况下，仪器会自动停止跟踪和停放，以避免过大的负荷。
The Light Cannon is a custom built optical machine mounted on the roof of a 16 story building that tracks the sun by movement on two axes. The front window is made out of floated borosilicate glass that filters out infrared and ultraviolet wavelengths. The mirrors inside the Cannon collect, concentrate and redirect visible solar radiation through the shaft below into the Redirecting Optics. The shape of the Cannon was designed to reduce windage for the instrument. Under high wind conditions the instrument is programmed to stop tracking and park itself to avoid excessive loads.
重定向光学系统由一系列镜子和透镜组成，它们为光线从光炮、16 层和17层的机械设备周围以及楼梯井顶部提供了一条通路，光线最终到达悬挂在光匕首上方的桁架上。同一光轴上的第二组光学器件在楼梯天花板上提供太阳圆盘的实时白光图像。
The Redirecting Optics consist of a series of mirrors and lenses that provide a pathway for the light to travel from the Light Cannon, around the mechanical equipment on the 16th and 17th floors, and into the top of the stairwell, terminating on a truss suspended above the Light Dagger. A second set of optics inhabiting the same light shaft provides the real time white light image of the solar disc on the ceiling of the stair.
从结构上看，匕首由四根张紧的钢缆支撑，钢缆从地面到天花板横跨整个楼梯高度。这些钢缆上悬挂着 16 个不锈钢环，间距为 15 英尺。匕首本身呈锥形，因此顶部的环最大，内径为 24 英寸，底部环的外径不到 10 英寸。每个环都是光匕首所有光学元件的连接点和接口。
Structurally, the dagger is supported by four tensioned steel cables that span the full height of the stair from the floor to ceiling. From these cables are hung 16 stainless steel rings, spaced 15’ apart. The Dagger itself is tapered in shape, so the top ring is the largest with an interior diameter of 24,” and at the bottom ring the outside diameter is less than 10”. Each ring acts as a connection point and interface for all the optical components of the Light Dagger.
在光环之间，光束通过悬挂的光纤到达一楼时是可见的。在夜晚或阴天，光匕首看起来几乎像一根凹槽柱，一系列高高的白色圆形纤维营造出这种效果。当太阳出来时，雕塑变得明亮，既提供了光线，又与天空相连。纤维两侧发出不同程度的光芒，亮点穿插其中，突出了每根纤维的末端。
Between rings, the light beam is visible through the hanging fibers as it travels down to the first floor. At night, or on a cloudy day, the dagger appears almost like a fluted column, with a series of tall white round fibers creating this effect. When the sun is out, the sculpture becomes bright, providing both light and a connection to the sky.Varying levels of glowing light emit from the sides of the fibers, with bright spots of light interspersed, highlighting the ends of each individual fiber.
光匕首上下对比透视图，显示模拟建筑（上）和竣工建筑（下）的表面亮度。在项目的设计阶段，我们使用了光度精确的光线追踪软件（Radiance），并制作了光雕与拟建楼梯间的高动态范围（HDR）效果图。模拟包括建议的电力照明方案，使用制造商的 IES光度文件作为每个灯具的输入。下边的图片是用校准过的相机拍摄的雕塑成品的真实照片，经过后期处理后亮度比例与模拟图相同。模拟的输入是通过测量我们在实验室中设置的全比例光纤束模型得出的。结果证明模拟是保守的，因为我们假定光纤束中的光损耗较高，因此雕塑的亮度比预期的要高。
Side-by-side falsecolor comparison perspective view of Light Dagger showing the surface brightness (luminance) for both simulated (up) and completed building (down). During the design phase of the project, we used photometrically accurate ray-tracing software (Radiance) and created high dynamic range (HDR) renderings of the light sculpture in context with the proposed stairwell. The simulation included the proposed electric lighting scheme using manufacturer’s IES photometric files as input for each of the luminaires. The image on the right is a real photograph of the finished sculpture taken with a calibrated camera and post-processed to the same brightness scale as the simulation. The input for the simulation was derived by measuring a full scale mockup of the fiber bundles that we setup in our lab. The simulation turned out to be conservative as we had assumed higher light losses in the optical train, and therefore the sculpture resulted in being brighter than anticipated.
屋顶 “光炮 ”的轴侧剖面图，显示了用于将阳光集中并重新导向建筑内部的镜面系统。
项目详情
地点：纽约州 纽约市
项目团队：建筑师 George Loisos；核心团队 Eduardo Pintos、Susanna Douglas、Susan Ubbelohde；项目团队 Alan DeMarche、Steven Eichbaum
备案建筑师 HLW - Lee Devore
望远镜控制 Starman Systems - Richard Treffers
结构工程师：Mar 结构设计公司
光学设计与制造：Optical Mechanics, Inc.
主镜制造：Displays and Optical Technolgies, Inc.
摄影：Nicholas Venezia / George Loisos
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