Kostenloser Licht Pollution Impact Rechner
Schätzen Sie how light pollution affects astrophotography contrast. Kostenloser sky-brightness Rechner.
Sky-to-Object Flux Ratio
15.8489
Sky-to-Object Flux Ratio vs Sky Brightness
Formel
## Light Pollution and Contrast Light pollution raises the sky background, drowning out faint objects. ### Key Relation The flux ratio of sky to object is: **ratio = 10^((mag_obj - mag_sky) / 2.5)** A higher ratio means the sky overwhelms the target. Object contrast is approximately 1 / (1 + ratio). Darker skies (higher mag/arcsec2) dramatically improve contrast for faint targets.
Lösungsbeispiel
Sky = 19 mag/arcsec2 (suburban), object = 22 mag/arcsec2.
- 01ratio = 10^((22 - 19) / 2.5)
- 02ratio = 10^1.2 = 15.85
- 03contrast = 100 / (1 + 15.85) = 5.94%
- 04The object has only 5.9% contrast against the bright sky.
Häufig Gestellte Fragen
What is a good sky brightness for deep-sky imaging?
Bortle 3 or darker (about 21.5 mag/arcsec2 or higher) is excellent. Bortle 7 suburban skies (about 19 mag/arcsec2) are challenging for faint nebulae.
Do narrowband filters help?
Yes. Narrowband filters reject broadband light pollution while passing specific emission lines (H-alpha, OIII), dramatically improving contrast.
Can I subtract sky background in software?
Partially. Software can subtract the smooth background, but the shot noise from bright skies remains and limits the achievable SNR.