Calculateur de Signal sur Bruit par Empilement
Calculez l'amélioration du rapport signal sur bruit par empilement d'images.
Stacked SNR
50.0000
Stacked SNR vs Single-Frame SNR
Formule
## Signal-to-Noise Improvement from Stacking Stacking multiple exposures averages out random noise while the signal adds coherently. ### Formula **SNR_total = SNR_single * sqrt(N)** - *N* = number of stacked frames Doubling the SNR requires four times as many frames. This is the square-root law of signal averaging.
Exemple Résolu
Stack 100 frames each with SNR = 5.
- 01SNR_total = SNR_single * sqrt(N)
- 02SNR_total = 5 * sqrt(100)
- 03SNR_total = 5 * 10 = 50
Questions Fréquentes
Is stacking better than one long exposure?
For the same total time, ideally they are equivalent. In practice, stacking is better because it allows rejection of satellite trails, cosmic rays, and bad frames.
Does this assume noise is random?
Yes. The sqrt(N) law applies to uncorrelated random noise (shot noise, read noise). Systematic patterns (e.g., vignetting) must be removed separately.
How many frames do I need?
For a 10x SNR improvement you need 100 frames. For 3x you need only 9. Diminishing returns set in at high frame counts.