It shows that the differential focussing method by comparing MTFs has perfect performances high speed, high precision focussing, not being affected by image displacement and flexibility etc.
实验表明，差分式对比传递函数法调焦，具有调焦精度高，调焦速度快，受像移影响不明显，适应性好等优点。
3
Numerical method of integral order ordinary differential equation, for example, Euler method, linear multiple step method, and so on, has had quite perfect theories.