浙江单阳县周月景同志问:高反差低速胶片采用什么方法加厚或减薄,才能达到较理想的效果? 答:关于低感光度高反差胶片减薄与加厚的问题,现提出两种方法供参考试用。一、铁铵矾减薄法在酸性介质中,铁盐也可用来使银氧化,用硫酸铁铵的酸性溶液处理胶片时,可以得到比减的效果。 Comrade Zhou Yuejing of Shanyang County, Zhejiang Province, asks: What methods of high-contrast low-speed film are thicker or thinner in order to achieve better results? A: With regard to thinning and thickening of low-sensitivity and high-contrast films, two methods are proposed For reference trial. First, ammonium ferric sulphate thinning method In acidic medium, iron salts can also be used to make silver oxidation, with ferric ammonium sulfate solution of the acidic solution, you can get less than the effect.