合影中对焦位置的确定

Focus Location Ascertainment of Group Photo

在没有装足够大底片的相机(或转机)或者天气亮度不足的情况下,通过几何图表和数学计算找出最佳聚焦位置,保证合影中每一个人都尽可能地清晰,为拍摄提供方便依据.

That in the absence of large enough backing film camera （ or panorma）, or the lack of brightness of the weather, through geometric diagrams and mathematical calculations find the best focus, and ensure that every person is as clear as possible is discussed in this paper, to provide a convenient basis for group photo taken.