def METHOD_NAME(flux, flux_error, zeropoint, exptime):
    """
    Convert flux to magnitudes
    Parameters
    ----------
    flux: float array
          flux measurements in counts
    flux_error: float array
                flux errors in counts
    zeropoint: float
               zeropoint in units of counts / s
    exptime: float
             Exposure time of the image (s)
    Returns
    -------
    magnitude: float array
               converted magnitudes
    magnitude_errors: float array
                      uncertainties on the converted magnitudes calculated with standard uncertainty propagation
    """
    mag = -2.5 * np.log10(flux / exptime) + zeropoint
    mag_error = 2.5 / np.log(10.0) * np.abs(flux_error / flux)
    return mag, mag_error