反差是影响影片质量的一个重要因素。要使一部影片的反差合适,首先要求照明布光合理,光比控制适当。其次要求洗印部门正确加工,合理控制底片和正片的反差。下面着重谈谈我对后期制作影片时合理控制反差的一点看法。底片反差的控制有多种方法,如:反差系数法,反差指数法,平均斜率法。现在大多用平均斜率法来控制黑白底片的显影程度, Contrast is an important factor affecting the quality of the video. To make the contrast of a film appropriate, first of all require reasonable illumination lighting, light control than appropriate. Second, the printing sector requires correct processing, reasonable control of negatives and positives. Here to focus on my post-production video reasonable control of the point of view. Negative control of film There are many ways, such as: contrast coefficient method, contrast index method, the average slope method. Now most of the average slope method to control the degree of black and white film development,