影像的来路：从光到信号Where Images Come From: Light to Signal
学习目标LEARNING OBJECTIVES
学完你能说清影像从光到屏幕的来路，以及「现在光是原生的」意味着什么。
概念说明CONCEPTS
来路四步：小孔成像（轻微带过）→ 影像被印在化学物质上 → 数码相机转成信号 → 信号进电脑用算法呈现——所以它变成了发光的。
传统电影：光外来，由胶片呈现；现在：光是原生的，屏幕与相机各异——不同屏幕、不同厂家的光和光的反应不一样，不同相机给人的感觉也不一样。
操作步骤STEPS
- 对着屏幕问：这块光是从哪来的
- 对比胶片放映与屏幕发光的差别
- 换一台设备看同一画面，记录观感差异
练习PRACTICE
动手任务
同一画面在两台不同设备上并排看，写下三条观感差异。
自检清单
做完任务后逐条自查，全部能打勾才算过。
常见问题FAQ
手机屏幕和影院银幕是一回事吗？
不是——一个是发光的原生光，一个是外来的反射；来路不同，呈现也不同。
传统电影和现在的影像，本质区别是什么？
传统电影的光是外来的，由胶片呈现；现在光是原生的，屏幕与相机各异。
Learning Objectives学习目标
After this card you can trace where images come from — light to signal to screen — and what "light is now native" implies.
Concepts概念说明
Four steps: pinhole imaging (in passing) → the image printed onto chemistry → digital cameras turn it into signal → the signal enters a computer and is rendered by algorithms — which is why it became emissive.
Traditional film: light comes from outside, the stock presents it; now: light is native, and screens and cameras all differ — different screens and makers produce different light and different reactions, which is why different cameras feel different.
Steps操作步骤
- Ask of any screen: where does this light come from
- Compare film projection with an emissive screen
- View the same picture on two devices and note three differences
Practice练习
Hands-on task
View the same picture on two different devices side by side and write down three differences.
Self-check
Work through the task, then tick every line; all checked means you own this card.
FAQ常见问题
Is a phone screen the same thing as a cinema screen?
No — one is emissive native light, the other external reflection; different origins, different rendering.
What fundamentally separates traditional film from today's images?
Traditional film: light comes from outside, shown by the stock. Now light is native — screens and cameras all differ.