Contrary to conventional wisdom, higher resolution actually compensates for noise

Sunday November 16 2008

Sensor Insight
Introduction | Modeling small pixels | Comparing the SNR of cameras with different resolutions | Real-life comparisons | Conclusion

Noise measurements in RAW format are indicative of pixel performance, but the viewing conditions of the image must also be taken into account. To compare prints on a given format of cameras with different resolutions, it is more suitable to compute the equivalent SNR of a camera with a given reference resolution. For equal, normalized SNR, a high-resolution camera is still better than a low-resolution camera. While it is always possible to simulate a low-resolution camera using a higher resolution camera (since downsampling is easy), it is not possible to simulate a high-resolution camera using a lower-resolution camera other than by interpolating or inventing data.