乌拉诺曝光计算器教程
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bob棋牌怎么样培训视频解释如何创建曝光测试。乌拉诺创作
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乌拉诺乳剂的处理是直接的，但它可能是有用的，以进一步了解如何确定适当的曝光时间的模板。为此，乌拉诺建议使用“阶梯楔形测试”。这是一系列的五次增量曝光，都是在同一个模板上制作的。该测试使用的胶片正片，旨在显示各种各样的线厚度与红宝石和琥珀石品牌掩膜。使用列出的大致曝光时间作为起点。将涂了涂层的屏幕和正片贴在上面，放在一个真空框架中，让光源曝光大约50%的时间。第二次曝光时，将掩蔽膜粘在适当的位置，使其覆盖大约五分之一的正片，然后再次曝光，这次曝光时间为大约曝光时间的25%。移动掩模，使其覆盖正片的五分之二，然后再次曝光大约曝光时间的25%。继续移动掩模膜超过正片的五分之三，像上一步一样曝光。没有覆盖最终曝光的五分之四的正面。 Of course the percentages of the exposure can be varied as desired. But the end result will still be a stencil with the approximate exposure, and two exposures above and below this approximate time. Process the stencil as before and dry. When the stencil is ready, make a print from it. After the print dries, compare it to the film positive. Usually the highest exposure consistent with resolution and adhesion requirements gives the best edge definition and greatest wear characteristics. But bear in mind that the finer the printed detail is desired, the more carefully over-exposure must be prevented. The area of best exposure will be where there is no change in the emulsion color, or where the film positives outline is no longer observable with increased exposure. Ultimately the step wedge test is valuable insurance against wasted time and materials.
