Photon Statistics and Localization Microscopy
Change the number of detected photons, the background, the PSF width, and an astigmatism-like z parameter. Watch how shot noise makes images grainy and how fitting the PSF lets us estimate the emitter center with subpixel precision.
Shot noise scale √N
28.3
Measured localization precision
0.07 px
Simple prediction σ/√N
0.05 px
Current fitted center
8.35, 7.65
Simulated Camera Frame and Fitted PSF
Profiles Through the PSF
Repeated Localizations and Precision
Main ideas
Photon counting noise scales roughly as √N, so brighter emitters look less noisy.
Localization microscopy extracts the center of the diffraction-limited PSF by fitting it, which can achieve subpixel precision.
Here the z slider changes the PSF widths in x and y as a simple astigmatism-inspired proxy for 3D localization.