The two Gemini observatories (www.gemini.edu) were built and are operated by a partnership of seven countries including the United States, United Kingdom, Canada, Chile, Australia, Brazil, and Argentina. Astronomers in each of these countries are able to apply for time on the telescopes for scientific research. Gemini sets strict technical requirements on many aspects of the filters used on the telescope including a strict requirement that they be extremely flat—their total deviation from absolute flatness must be no more than 30 nm as measured by the root mean square deviation. How should filter manufacturers view this requirement, as a control or specification limit? Explain.