目前,我厂对黑白文字、线条及半色调阴图进行照相和拷贝所使用的感光材料是化工部第一胶片厂生产的特硬正色片,这种软片的感光度较高。反差大,解象力较好。拍摄所得的文字光学密度合适、线条粗细适中,清晰度较高,文字、符号角度变圆的现象很小,且版面均匀,灰雾度低。通过近期的使用,我们对这种软片的性能有了一定的了解,现介绍如下: Currently, our factory for black and white text, lines and half-tone negatives for photographic and copying the photosensitive material used by the Ministry of Chemical Industry’s first film factory production of special hard-normal color film, this high sensitivity film. Large contrast, better solution. Filming the resulting text Optical density is appropriate, the line thickness is moderate, high definition, text, symbols rounded phenomenon is very small, and the layout is uniform, low fogging. Through the recent use, we have a certain understanding of the performance of this film, are presented below: