NEW Instructions for Using CaliBall


Using the CaliBallTM to calibrate interferometer transmission or reference spheres using the random ball test is almost fool proof.

However, observing a few simple precautions will improve the results of the calibration.

These precautions are detailed in the "Instructions for Using CaliBall" in approximately the order they should be followed.

Read instructions

About the Author

Robert Parks

Robert Parks

Mr. Parks received a BA and MA in physics from Ohio Wesleyan University and Williams College, respectively. His career started at Eastman Kodak Company as an optical engineer and then went on to Itek Corp. as an optical test engineer.

He learned about optical fabrication during a 4 year stay at Frank Cooke, Inc. This experience led to a position as manager of the optics shop at the College of Optical Sciences at the Univ. of Arizona and where he worked for 12 years and had a title of Assistant Research Professor. During that time he had the opportunity to write about the projects in the shop and the optical fabrication and testing techniques used there including papers about absolute testing and the installation and used of a 5 m swing precision optical generator.

Mr. Parks left the University in 1989 to start a consulting business specializing in optical fabrication and testing. Among the consulting projects was one working for the Allen Board of Investigation for the Hubble Telescope where he stayed in residence at HDOS for the duration of the investigation. In 1992 he formed Optical Perspectives Group, LLC as a partnership with Bill Kuhn, then a PhD student at Optical Sciences.

The consulting and experience with Optical Perspectives provided many more opportunities to publish work on optical test methods and applications. While still at Optical Sciences, Mr. Parks became involved in standards work and for twenty years was one of the US representatives to the ISO Technical Committee 172 on Optics and Optical Instruments. For two years he was the Chairman of the ISO Subcommittee 1 for Fundamental Optical standards. Recently Mr. Parks temporarily rejoined Optical Sciences part time helping support optical fabrication projects and teaching as part of the Opto-Mechanics program.

Bob is a member of the Optical Society of America, a Fellow and past Board member of SPIE and a member and past President of the American Society for Precision Engineering. He is author or co-author of well over 100 papers and articles about optical fabrication and testing, and co-inventor on 6 US patents. He remains active in development of new methods of optical testing and alignment.

Case Studies & Testimonials

Why is proper alignment so important?

Here is a case of a very happy customer due to better optics.

A few days ago an astronomer friend of mine commented that he had gotten the optics of his telescope improved and the improvement reduced the time it took to get data by a factor of 3. For an astronomer this is a dramatic improvement since observing time on large telescopes can cost thousands of dollars an hour.

My friend did not say how the optics had been improved, but the important point is that better optics, whether due to figure errors, mounting or alignment mean more productive optics. I generally think of better optics as a better product leaving the manufacturing facility without thinking about how much the better optics mean to the productivity of the customer.