black card

基本解释

A black card is just a regular cardboard paper. The key point is the color black. Black absorbs light. Therefore, the camera will not capture the black card.
黑卡，就是一般的紙，重點是要黑色，黑色會吸光，如此相機才不會拍攝出這片卡的顔色。
Try the technique before you buy with a DIY alternative. Roll a sheet of black card into a cone and place a strip of black or gaffer tape along the seam to hold it securely in place.
在買之前先自己DIY一個，把一張卡紙卷成圓錐型，用電工黑膠粘牢。
If you don't shake the black card, it will leave a very clear line on your photo.
若不晃動黑卡，影像中會畱下一條很明顯的直線。

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