中文说明：拍照时总是固定的焦点。通过采取同一场景用不同的焦点水平，你可以得到一个图像，整体锐利。色差（CA，也称为无色或彩色失真）[维基百科]的问题也解决了。（如果你有很多条）
English Description：
Taking pictures comes always with a fixed focus. By taking the same scene with different focuslevels you can get an image that is overall sharp.Chromatic aberration (CA, also called achromatism or chromatic distortion)[Wikipedia] -problems are also solved by this. (Important if you have a lot of bands)