Likewise, the thin lens equation is still applicable in most of our basic situations.
同样,薄透镜方程仍然 适用于我们的大多数基本情况。
Crash Course Physics 速成课物理
This is the thin lens equation, which is derived from ray diagram geometry.
这是薄透镜透镜方程,它是导数 从射线照相的几何形状。
Crash Course Physics 速成课物理
For a diverging lens, the thin lens equation is still true, but the focal length is now a negative value.
对于间隔透镜,薄透镜方程仍然是 正确,但现在的焦距是 负值。
英语百科
Lens (optics)
where M is the magnification factor defined as the ratio of the size of an image compared to the size of the object. The sign convention here dictates that if M is negative, as it is for real images, the image is upside-down with respect to the object. For virtual images M is positive, so the image is upright.