Diffraction scale and atmospheric seeing
A circular aperture has a diffraction angular scale proportional to wavelength divided by diameter.
Key knowledge
A circular aperture has a diffraction angular scale proportional to wavelength divided by diameter. Atmospheric turbulence can broaden a ground-based image beyond this scale; adaptive optics corrects measured wavefront distortions within its operating limits. Collecting more photons and resolving closer objects are distinct capabilities.
Values and equations
θ ≈ 1.22 λ/D
- θ
- circular-aperture diffraction angular scale rad
- λ
- wavelength m
- D
- aperture diameter m
Conditions and scope
- The 1.22 coefficient refers to the first minimum of the ideal unobscured circular-aperture Airy pattern and the associated Rayleigh separation convention.
- Aberrations, obscuration, sampling, contrast and atmospheric correction alter practical performance.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read the ISO instrument's explicit θ=1.22λ/D diffraction expression and OpenStax adaptive-optics discussion; the ideal-pattern condition is explicit in this record, not a universal instrument specification.
2026-10-10 · Independent AI editorial review: All26 Life-authored Cosmos compact statements, conditions, displayed equations and all56 origin semantic links read. Entire26-entry author statement/source matrix and explicit exclusions assessed. Targeted independent primary sections are listed below; this does not claim every referenced source body or proof was independently re-read. This is scoped AI reference-content review, not human disciplinary certification or whole-field completion. Receipt: cosmos-life-independent-content-review.1.
Entry details
Permanent link to this entry ↗- Record identity
- uni-cosmos-angular-resolution
- Revision
- core.1
- Structured reference record
- University core expansion