用鱼眼镜头数码相机测试天空亮度分布

Testing sky luminance distribution by fish-eye lens digital cameras

为了解决天空亮度测试中存在的同步性差和误差大的缺陷,采用带鱼眼镜头的数码相机测试天空亮度。通过对鱼眼镜头及数码相机光学特性的研究,得到从数码照片上提取被测天空元亮度及位置信息的方法,确定其曝光参数及线性亮度记录范围,并通过对相机稳定性、鱼眼镜头透光率等误差进行分析修正,获得了精度较高的天空亮度分布测试值。为采光研究及采光观测提供了重要的技术手段。

To solve the existence of poor synchronization and large error in the sky luminance test, using fish-eye lens digital camera test sky luminance. Through researching on fish-eye lens and the optical characteristics of digital cameras, get the method that extract the luminance and location information of the measured sky element from digital photos, and determine the exposure parameters and the record range of linear brightness. Analyzing and amending the stability of the camera and light transmission rate of fish-eye lens, get a more accurate test values of sky luminance distribution. This provide important techniques means for daylighting research and daylighting observation.