"失焦"是个多义词，它可以指失焦（摄影手记书籍）,失焦（2015年中国悬疑电影）,失焦（李禹东2015小说作品）。
FocusBlur：通过亮度和深度使图像失焦。
FocusBlur: Makes an image out of focus with luminosity and depth.
你对肖像照中的软失焦背景处理是对的，大多数情形下这是突出主体，并避免多余背景干扰的好方法。
You're right about the soft blurry backgrounds in portraits - in most cases they are a great way to highlight your main subject and get rid of any distractions in the background.
当你的想像失焦时，你就不能依赖你的眼睛了。
You cannot depend on your eyes when your imagination is out of focus.
应用推荐