Sheet lightning lights up the whole sky. It has no special shape. Sheet lightning is actually the light from a chain lightning flash that occurs very far away.
片状闪电照亮整个天空。它没有什么特殊的形状。片状闪电实际上是发生在很远的地方的链状闪电的光。
2
This exposure is made with a small F-stop to a sheet of white paper placed over the original, or to the rays from a flash - lamp.
闪光曝光，可用小光圈档，用一张白纸放在原稿上面或用闪光灯曝光。
3
For a fast dash of flash, top a dark countertop with a piece of hammered-aluminum sheet metal, available at home centers.