Discussion Overview
The discussion centers on the concept of wave rating in telescope mirrors, specifically what the term means and how it relates to the performance of telescope optics. Participants explore the implications of wave ratings for mirror quality and accuracy in the context of telescope design.
Discussion Character
- Technical explanation
- Conceptual clarification
- Debate/contested
Main Points Raised
- One participant notes that a telescope system should ideally have a wave rating of at least 1/4 wave or less for both primary and secondary mirrors combined, seeking clarification on what this measurement entails.
- Another participant explains that a "quarter-wave" mirror is defined as having a surface figure that deviates from an ideal parabola by no more than one quarter wavelength of a specific color of visible light, typically green.
- A further contribution emphasizes that while wave ratings are common, they may not be the best measure of mirror quality, suggesting that the "Strehl Ratio" is a more reliable indicator of surface accuracy.
Areas of Agreement / Disagreement
Participants generally agree on the definition of a quarter-wave mirror but express differing opinions on the relevance of wave ratings compared to the Strehl Ratio. The discussion remains unresolved regarding the best metric for assessing mirror quality.
Contextual Notes
There is mention of the specific wavelength used for measurements, with a note that using different wavelengths (e.g., red light) could lead to misleading assessments of mirror quality. The implications of these choices on practical performance are not fully explored.