由黑灰白不同密度组成的照片画面,如果影像的反差偏大,黑与白的对比就强烈,中间灰密度缺乏。所谓相纸的增感,是在相纸正常放大曝光之后,用放大机较弱的白光对着已经曝过光的相纸重新曝一次光,即用加灰的办法达到降低相纸反差的目的。 By black and white photos of different density composition of the screen, if the image contrast is too large, the contrast between black and white is strong, the lack of intermediate gray density. The so-called photographic paper sensation, photographic paper is normal enlarged exposure, with the weaker white light amplifier has been exposed to the light exposure of the photographic paper to re-exposure to light, that is, with the gray method to achieve the purpose of reducing paper contrast .