Tag: featured

On the Passage of Linearly Polarized Light through an Uncoated Roof Prism

September 20, 2024

The famous Zeiss “paper” by Weruach and Dörband (translation attached below) on the development of phase coatings for roof prisms describes a simple test to determine if an optical instrument has coated prisms or not. They describe the use of two linear polarizers with the device placed in between; with phase coating present, one will … More On the Passage of Linearly Polarized Light through an Uncoated Roof Prism

Some Thoughts on Bird Names and Barriers

November 8, 2023

Edit: New as of late June, 2024: Unlike the AOS, the AFO actually surveys its members: https://afonet.org/2024/06/afo-member-feedback-on-the-decision-from-aos-to-replace-all-eponymous-bird-names/ I post this with trepidation. I am disinclined to touch on such topics here. A few years ago, I became involved with a birding organization whose core mission of making birding more accessible deeply resonated with me. I … More Some Thoughts on Bird Names and Barriers

The Physics of Roof Prisms and Phase Coatings

July 22, 2023

I’ve written a technical article on the topic of why the roof prisms used in binoculars require specialized coatings in order to improve their performance. I was prompted to pull this together because I couldn’t find a single reference that traced through this interesting problem in a non-trivial way. The article includes a derivation of … More The Physics of Roof Prisms and Phase Coatings