Reconstruction rms as a function of photon flux per spectral channel. The blue circles show the rms of a classic SCC, and the orange triangles show the rms of the SM-SCC. The dashed lines are fits of the expected N^−1/2 behavior due to photon noise. Around a photon flux of 10⁹ − 10¹⁰, the curve of the SM-SCC starts to flatten out due to intrinsic reconstruction errors. For a classic SCC, this happens at a higher photon flux but at a similar reconstruction rms. The input rms was 30 nm, which indicates that both sensors can reconstruct the wavefront with errors smaller than 5% at high flux levels.