在放黑白照片时,经常遇到底片反差、密度大小不一的情况,这给放制黑白照片带来难度,要缩小黑白照片中高密度部分与低密度部分过大的差距,在放制过程中可以采用局部加光法,也可以采用局部遮挡法。当黑白照片中需要遮挡的部分比较少时,用局部遮挡方法对黑白照片中低光、高光部分进行适当的遮挡,以提高黑白照片中的层次质量,达到最佳的黑白灰效果。采用局部遮挡的方法,可以提高 In black and white photos, often encounter film negative contrast, the density of different sizes, which gives the black and white photographs to bring difficulty, to reduce the black and white photographs of high-density parts and low density part of the gap is too large, in the release process You can use local light method, you can also use the local occlusion method. When the black-and-white photos need to block the part is relatively small, the use of partial occlusion method of black and white photos of low light, high light part of the appropriate occlusion to improve the quality of black and white photographs in order to achieve the best black and white gray effect. The method of partial occlusion can be improved