Video: Optical Coatings and Oilings for Astronomical Instruments with Alan Ward

The optical surfaces of all modern quality astronomical instruments are either coated and/or oiled-spaced with extremely thin layers of metallic/dielectric or liquid materials to improve optical performance. This presentation will describe the mechanics of depositing these materials and the theory of thin-film interference, and give an overview of what every telescope user should know about the many available optical coatings/oilings for lens/mirrors and how to care for them.

Alan Ward gave this presentation to the online meeting of the Recreational Astronomy Night, which was held by RASC, Toronto Centre on May 5, 2021. Alan is president of the RASC, Sudbury Centre.