摄影曝光中的杠杆平衡原则

目的：使摄影曝光学的理论和运用由繁琐变得简洁明了。方法：在传统的曝光指数方程的基础上，运用了数学推理和物理中的杠杆平衡理论。结果：得到了曝光指数变量方程和杠杆平衡原则。结论：曝光指数变量方程及其应用中的杠杆平衡原则是一种更直观快捷的新理论，使摄影曝光学的理论和运用得到了升华。

Level Principle for Exposure in Photography

Object：The amount of light to which film is exposed is an important factor in photography. To quickly obtain an optimum exposure, an easy and simple new method is introduced. Method： On the basis of the difference of exposure index, lever principle that normally applies to mathematics and physics is employed. Results：Develop an exposure level principle and create an exposure dial. Conclusion：The teaching and practice application proved that the exposure level principle is a visual and fast way to find out an optimum exposure parameter, the shutter speed and aperture. This exposure difference index extends the photography theory to the practice very well.