black and white photography

Though fluorescent whitening agents can improve significantly the whiteness of black-and-white photographic paper's image picture, this effect may be reduced owing to the shift of whitener molecules during the photographlc processing and induced by acids, alcalis and washing.

提高黑白照相纸影像画面白度的主要方法之一是荧光增白剂的采用，但由于荧光增白剂分子易受加工过程中的酸碱和漂洗的影响而流失，从而降低了影像画面的白度。