Abstract：
OBJECTIVE: Investigate the visibility of new and old red, white and pink cricket balls under lighting and background conditions experienced during a day-night cricket match.
METHODS: We modelled the luminance contrast signals available for a typical observer for a ball against backgrounds in a professional cricket ground, at different times of day.
METHODS: Spectral reflectance (light reflected as a function of wavelength) was derived from laboratory measurements of new and old red, white and pink balls. We also gathered spectral measurements from backgrounds (pitch, grass, sightscreens, crowd, sky) and spectral illuminance during a day-night match (natural afternoon light, through dusk to night under floodlights) from Lord\'s Cricket Ground (London, UK). The luminance contrast of the ball relative to the background was calculated for each combination of ball, time of day, and background surface.
RESULTS: Old red and old pink balls may offer little or no contrast against the grass, pitch and crowd. New pink balls can also be of low contrast against the crowd at dusk, as can pink and white balls (of any age) against the sky at dusk.
CONCLUSIONS: Reports of difficulties with visibility of the pink ball are supported by our data. However, our modelling also shows that difficulties with visibility may also be expected under certain circumstances for red and white balls. The variable conditions in a cricket ground and the changing colour of an ageing ball make maintaining good visibility of the ball a challenge when playing day-night matches.
METHODS: We modelled the luminance contrast signals available for a typical observer for a ball against backgrounds in a professional cricket ground, at different times of day.
METHODS: Spectral reflectance (light reflected as a function of wavelength) was derived from laboratory measurements of new and old red, white and pink balls. We also gathered spectral measurements from backgrounds (pitch, grass, sightscreens, crowd, sky) and spectral illuminance during a day-night match (natural afternoon light, through dusk to night under floodlights) from Lord\'s Cricket Ground (London, UK). The luminance contrast of the ball relative to the background was calculated for each combination of ball, time of day, and background surface.
RESULTS: Old red and old pink balls may offer little or no contrast against the grass, pitch and crowd. New pink balls can also be of low contrast against the crowd at dusk, as can pink and white balls (of any age) against the sky at dusk.
CONCLUSIONS: Reports of difficulties with visibility of the pink ball are supported by our data. However, our modelling also shows that difficulties with visibility may also be expected under certain circumstances for red and white balls. The variable conditions in a cricket ground and the changing colour of an ageing ball make maintaining good visibility of the ball a challenge when playing day-night matches.
摘要：
目的：调查新旧红色的可见度，在昼夜板球比赛中经历的照明和背景条件下的白色和粉红色板球。
方法：我们模拟了在专业板球场背景下的典型观察者可用的亮度对比信号，在一天的不同时间。
方法：光谱反射率（作为波长的函数反射的光）是从实验室测量的新旧红色，白色和粉红色的球。我们还收集了来自背景的光谱测量值(音高，草,视屏,人群,天空)和昼夜比赛期间的光谱照度(下午自然光线，通过黄昏到晚上在泛光灯下)从Lord\的板球场(伦敦，英国）。对于每个球的组合，计算球相对于背景的亮度对比度，一天的时间,和背景表面。
结果：旧红色和旧粉红色的球可能与草形成很少或没有对比，球场和人群。新的粉红色球也可以在黄昏时与人群形成较低的对比，黄昏时，粉红色和白色的球（任何年龄的）对着天空。
结论：我们的数据支持了粉红色球可见性困难的报告。然而,我们的建模还表明，在某些情况下，红球和白球的能见度也可能会出现困难。板球场的变化条件和老化球的颜色变化使保持球的良好可见度成为昼夜比赛时的挑战。
方法：我们模拟了在专业板球场背景下的典型观察者可用的亮度对比信号，在一天的不同时间。
方法：光谱反射率（作为波长的函数反射的光）是从实验室测量的新旧红色，白色和粉红色的球。我们还收集了来自背景的光谱测量值(音高，草,视屏,人群,天空)和昼夜比赛期间的光谱照度(下午自然光线，通过黄昏到晚上在泛光灯下)从Lord\的板球场(伦敦，英国）。对于每个球的组合，计算球相对于背景的亮度对比度，一天的时间,和背景表面。
结果：旧红色和旧粉红色的球可能与草形成很少或没有对比，球场和人群。新的粉红色球也可以在黄昏时与人群形成较低的对比，黄昏时，粉红色和白色的球（任何年龄的）对着天空。
结论：我们的数据支持了粉红色球可见性困难的报告。然而,我们的建模还表明，在某些情况下，红球和白球的能见度也可能会出现困难。板球场的变化条件和老化球的颜色变化使保持球的良好可见度成为昼夜比赛时的挑战。
