免费透镜方程计算器
使用薄透镜方程计算物距、像距或焦距。
像距
15.00 cm
Image Distance vs Focal Length
公式
## Thin Lens Equation The thin lens equation relates object distance, image distance, and focal length. ### Formula **1/f = 1/d_o + 1/d_i** Positive focal length for converging lenses, negative for diverging. Magnification: **M = -d_i / d_o**. Negative M means inverted image.
计算示例
An object 30 cm from a converging lens with focal length 10 cm.
- 011/f = 1/do + 1/di
- 021/10 = 1/30 + 1/di
- 031/di = 1/10 - 1/30 = 3/30 - 1/30 = 2/30
- 04di = 15 cm
- 05M = -15/30 = -0.5 (inverted, half size)
常见问题
What does a negative image distance mean?
A negative image distance means the image is on the same side as the object (virtual image). This happens when the object is inside the focal length.
What is a virtual image?
An image that cannot be projected onto a screen. Light rays appear to diverge from the image location but do not actually pass through it.
How does a magnifying glass work?
By placing an object inside the focal length of a converging lens, creating an enlarged virtual image.
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