How to Use the Stouffer 21 Wedge
There are many different ways for exposing plates. There are an abundance of different exposure systems and processing techniques. The one constant is the step tablet/wedge. Use the step tablet/wedge as a benchmark for all exposures to achieve accuracy and repeatability.
See Table at right for densities. The approximate density of each step is listed in the Target column with tolerances listed to the right.
1. Set your contact printer or vacuum frame to make several trial exposures on separate pieces of film or photographic plate, with each exposure for a different length of time.
2. Make three exposures: one determined by past experience or the exposure normally used in daily production, one for less, and then one for more. It may be necessary to repeat this testing procedure using different exposure times.
3. Process the film or plate for the time and temperature recommended by the manufacturer. It is important to keep processing consistent.
4. Examine the step tablet/wedge image on each of the negatives and select the exposure that is the closest to what the manufacturer recommends for that product.
5. To find the exposure factor to hold more or less on the Stouffer 21 Step Platemaker Sensitivity guide, follow the chart below.