An Unexpected Harvest in the Darkroom

Hearing Ao Fei's answer, Qu Bing also felt it was a great pity. The lifelike portrait was right before their eyes, yet unfortunately, they had no way to preserve the image.

Ao Fei opened the doors and windows in dejection, then extinguished all the calcium carbide lamps. However, he did not put away his photography equipment. He simply left it there. Qu Bing continued circling it, looking from one side to another, and discovered that even under the natural light entering through the open doors and windows, an image could still be left on the ground glass inside the box. As he pondered this, he could not help discussing it with Ao Fei.

"Senior Brother, what conditions do you think we need to satisfy to preserve the inverted image?"

Although Ao Fei did not know the answer, he had already come up with a clear line of thought. He analyzed, "You said what we're seeing now is definitely an optical image, right?"

"Mm." Qu Bing immediately nodded.

"Our goal is to preserve the inverted image brought by the light onto a plate, right?"

"Mm-hmm. And then?" Qu Bing nodded again.

"So we should find a way to work on the plate—to create a plate that changes when exposed to light. That might serve some purpose. Even if it only gives us a direction, that would be good. Then I'd have the motivation to continue researching.

"You have no idea. I've already tried all kinds of materials: wooden boards, bamboo boards, copper plates, iron plates, lead plates, silver plates, gold plates, tin plates, glass plates. I've tested almost everything the Han Tribe currently has. I've also experimented with different exposure times, as well as comparing exposure under natural light and lamplight. But none of those things showed the slightest reaction. I'm