“雷登滤镜”(Wratten)

从“听罗伯韩特教授讲颜色”一文看到雷登滤镜，好奇查了一下，得到不少东西

“雷登滤镜”Kodak-WrattenFilters 是柯达公司的一款滤镜品牌，而对应的Wratten number是滤镜的一种编号体系。

Wratten numbers are a labeling system for optical filters, usually for photographic use comprising a number sometimes followed by a letter. The number denotes the color of the filter, but is arbitrary and does not encode any information (the 80A–80D are blue, the next filters in numerical order, 81A–81EF, are orange); letters increase with increasing strength.

滤镜在网上可以买到，这个样子,在万能的淘宝查了一下，也能买到，不过名字成了“天芬/Tiffen”，记得之前有一个关于柯达色卡的，色卡名字也成了“天芬/Tiffen”不知是不是因为柯达破产的缘故

相关资料：https://en.wikipedia.org/wiki/Wratten_number