Given a double perforated (I), (II), (III), or (IV) it is easy to make a double perforated optical print which is any of the four.
Single perforated films are a pain in the side. Given, for example, (IIIa), it is possible with a usual optical printer to make either (Ib), (IIb), (IIIa), or (IVa), but none of the other four. These could be made via a double perforated intermediate. With a prism or other image rotator, or a special reversed gate, it is possible to convert any of the eight ways to any of the eight ways. Figuring out how to do these is a good exercise for the student.
The two non-sham emulsion positions are sketched again, this time with emulsions facing in shown dotted.
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Notice that when pictures “read right” single perfs are on the left, and “before” is above.
Notice that camera original reads right with emulsion facing away. Contact print of camera original reads right with emulsion facing toward the viewer.
Except when optical printing is done in alliance with contact printing, it is usual to maintain emulsion position through all optical printing steps. Starting with camera original each generation is again (IIIa). For this there is a simple rule.
@@ -377,7 +377,7 @@A filter which absorbs the ultraviolet, such as Wratten 2B or 2E improves sharpness with almost all lenses.
Also, printing color film onto color film, or B&W film onto color film, there is color reproduction advantage to using a UV filter.
-Some color rawstooks have such filtration built in, some don’t.
+Some color rawstocks have such filtration built in, some don’t.
Even printing color film onto B&W film there is tonal advantage to using a UV filter.