Scientists added a red filter to film the movements.

科学家们添加了一个红色滤镜来拍摄这些动作。

I have never forgotten the corpse's close-up, shot through a red filter and a distorting lens which elongated the face into a huge silent scream.

我永远也忘不了那具尸体的特写镜头，是透过红色滤光镜拍的，镜头把那张脸拉长变形，呈现出无声尖叫的震撼形象。