Distribution of the standard deviation of the light curves obtained from our custom-made photometry (blue solid line) and directly from the ZTF data release DR11-psf light curves (pink dashed line) for four types of objects in the labelled set: non-variable stars, non-variable galaxies, low-redshift AGN (z < 0.5), and mid-redshift AGN (0.5 < z < 3). The standard deviation is calculated from the magnitudes.