Accurate Measurement of Daylit Interior Scenes Using High Dynamic Range Photography

10 pagesThis paper investigates accuracy in typical High Dynamic Range (HDR) photography techniques used by researchers measuring high resolution luminance information for visual comfort studies in daylit spaces. Vignetting effects of circular fisheye lenses are investigated for reproducibility between different lenses of the same model and sharing between researchers. The selection of aperture size is related to vignetting intensity, dynamic range and potential for lens flare. Lighting variability during capture processes is also tracked, and it is recommended to measure vertical illuminance in order to validate the stability of a scene. Finally, luminous overflow—a concept where a HDR photograph cannot measure the true luminous environment—is introduced. Its effect on the glare metrics UGR and DGP is investigated by using neutral density (ND) filters to increase the dynamic range of photographs under direct sunlight. It is recommended to use ND filters in scenes with vertical illuminances greater than 5 000 lx or with direct vision of the sun

Improving the Accuracy of Measurements in Daylit Interior Scenes Using High Dynamic Range Photography

8 pagesMeasuring the luminous environment enables researchers and practitioners to study perception and visual comfort in existing environments in order to decipher the components that contribute to good or problematic lighting characteristics. High dynamic range photography is commonly used to study visual perception and comfort. This paper presents new findings and specific methods of capturing interior scenes that may include peaks caused by a direct view of the sun and specular reflections. Methods are tested to improve the range of luminance values that can be captured, and new guidelines are proposed to improve the accuracy of computed visual comfort indices. Keywords: daylighting, high dynamic range imagery, visual comfort, glare, luminous overflow

A Passively Climatized Building, 2500 m Above Sea Level

After many years of research, Bakirlitepe-Saklikent near Antalya was selected as the site for Nationl Observatory of Turkey. Bakirlitepe, which can be classified within the best locations whole over the world for observation purposes has an altitude of 2547 m. Close to the observatory buildings a main building for the observers to rest and sleep during daytime had to be designed and constructed. There were many environmental and functional restrictions for the design. The clear sky, which increases the opportunity for observation and results in high solar radiation values, reminded the designers of the potential of solar utilization. The restrictions that shaped the building, the passively climatized architectural features and the thermal analysis are described in the paper

Per-Pixel Lighting Data Analysis

This report presents a framework for per-pixel analysis of the qualitative and quantitative aspects of luminous environments. Recognizing the need for better lighting analysis capabilities and appreciating the new measurement abilities developed within the LBNL Lighting Measurement and Simulation Toolbox, ''Per-pixel Lighting Data Analysis'' project demonstrates several techniques for analyzing luminance distribution patterns, luminance ratios, adaptation luminance and glare assessment. The techniques are the syntheses of the current practices in lighting design and the unique practices that can be done with per-pixel data availability. Demonstrated analysis techniques are applicable to both computer-generated and digitally captured images (physically-based renderings and High Dynamic Range photographs)

Transformations in architectural lighting analysis: Virtual Lighting Laboratory.

Lighting can be better analyzed and integrated in the architectural design process through computational tools. The dissertation presents a framework for a computer generated luminous environment that supports the knowledge acquisition between the theory and the practice of architectural lighting. Most of the current lighting analyses provide tenuous links to real world applications: their theory and the methodologies are based on predominantly simplified assumptions; their applications are limited; and the indicators are based on instantaneous lighting values that ignore temporal and spatial variations. Virtual Lighting Laboratory (VLL) proposes transformations in the utilization of physically based digital images in lighting analysis and the design decision-making process. Digital images are transformed into lighting laboratory or design settings where the user possesses manipulative and predictive power over a variety of lighting parameters and indicators. Per-pixel lighting information is extracted from the high dynamic range images through virtual meters and photometry systems. Formation and utilization of these virtual meters (luminance meter, illuminance meter, contrast meter, integrating sphere, colorimeter, and scotopic meter) are demonstrated. In the VLL, various analysis methods come together to support and complement each other. The total, regional, and per-pixel lighting data are processed through built-in functions to study the quantity, distribution, directionality, and spectral content of lighting. The current analysis techniques are thus utilized with additional advantages. The VLL also offers unique analysis options and metrics that are pertinent to the computational approach. The high resolution measuring capabilities and novel data analysis techniques lead to the exploration and generation of new lighting indices. The transformation of psychophysical experiments from laboratory environments to real world environments is supported. On the whole, the dissertation demonstrates the flexibility of capabilities within a virtual laboratory environment to handle various lighting design and analysis problems as opposed to imposing limited number of predetermined lighting tools and metrics.Ph.D.ArchitectureCommunication and the ArtsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124081/2/3121949.pd

Analysis of Thermal Performance of a Building Design Located at 2465: Antalya - Saklikent National Observatory Guesthouse

This study is based on thermal performance analysis and evaluation of the National Observatory guesthouse with the software SUNCODE-PC. The study is unique owing to its high-altitude site (2465 m) in a remote area, harsh climate (with almost no data available), and functional restrictions of astronomical facilities. The design is thermally evaluated through differant modes of application of insulation, materials, types of glazing, window/wall-ratios, Trombe walls, winter night insulation, summer ventilation and shading

Evaluation of High Dynamic Range Photography as a Luminance Mapping Technique

The potential, limitations, and applicability of the High Dynamic Range (HDR) photography technique is evaluated as a luminance mapping tool. Multiple exposure photographs of static scenes are taken with a Nikon 5400 digital camera to capture the wide luminance variation within the scenes. The camera response function is computationally derived using the Photosphere software, and is used to fuse the multiple photographs into HDR images. The vignetting effect and point spread function of the camera and lens system is determined. Laboratory and field studies have shown that the pixel values in the HDR photographs can correspond to the physical quantity of luminance with reasonable precision and repeatability

Thermal performance optimization of building aspect ratio and south window size in five cities having different climatic characteristics of Turkey

The aim of the study is to establish optimum building aspect ratios and south window sizes of residential buildings from thermal performance point of view. The effects of 6 different building aspect ratios and eight different south window sizes for each building aspect ratio are analyzed for apartments located at intermediate floors of buildings, by the aid of the computer based thermal analysis program SUNCODE-PC in five cities of Turkey: Erzurum, Ankara, Diyarbakir, Izmir, and Antalya. The results are evaluated in terms of annual energy consumption and the optimum values are driven. Comparison of optimum values and the total energy consumption rates is made among the analyzed cities