| A must for every shop. Allows you to avoid under and over exposing capillary film and liquid emulsion. The bottom half of the photo is the Exposure Calculator. You lay this over the emulsion or capillary film and expose like any positive. However, the first time you expose, also lay over the top half of the photo which is a filter. The filter is marked with numbers indication how much light goes through that portion of the filter. So .5 means 50% of the light passes through. If the light is on 10 minutes, the .5 section received the equivalent of 5 minutes of light. The objective is to find the time which is clearly more light than is necessary and the time that is clearly insufficient. Then remove the emulsion or capillary film from the screen, apply new emulsion or capillary film, and run the test without the filter. On this test cover all sections that are marked, except one. Turn the exposure light on for a short time like 15 seconds. Light off. Pull the cover back and expose again for 15 seconds. Repeat. The last section to be uncovered should be exposed for the time you calculated was insufficient to expose the screen. Then each section will be that time, plus the number of 15 second additions. Wash out the screen, and select the least time that gives you an excellent image. |
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