Fonda S, Gatti A M, Vecchi D
Acta Ophthalmol (Copenh). 1983 Feb;61(1):58-66. doi: 10.1111/j.1755-3768.1983.tb01395.x.
The authors test the hypothesis of systematic errors in photometric and/or densitometric measurements performed by Fundus camera equipment. By means of 2 different methods (reflection and transmission) the non-uniformity of light-distribution on sample surfaces placed in front of the fundus camera is shown. The consequent point by point variability in retinal illumination can be defined as the 'retinal shading problem'. This conclusion must be taken into account when equidensitometric measurements are carried out on eye fundus images with fundus camera, by photographic, cinematographic or TV techniques.
作者检验了眼底相机设备进行的光度和/或密度测量中存在系统误差的假设。通过两种不同方法（反射和透射），展示了置于眼底相机前的样本表面上光分布的不均匀性。视网膜照明中随之出现的逐点变化可被定义为“视网膜阴影问题”。在用眼底相机通过摄影、电影摄影或电视技术对眼底图像进行等密度测量时，必须考虑这一结论。
