WillHartley

 Top left: residual Top right: model Bottom left: science image. From the residual it looks like the model fitting is not completely breaking down, the negative...

It's really persistent isn't it.... Is there some way to translate the chi-sq scale param to an effective gain? Depending on how the coadd was constructed, you might want to...

This seems like the answer. I don't recall exactly what Emmanuel said on the call, but I think the essence of it was that the chi-2 scale was doing the...

Emmanuel should probably check this, but I think what you want is, poisson_noise = numpy.sqrt(numpy.fabs(img_data)\*exp_time\*gain)/(exp_time\*gain) total noise = numpy.sqrt(poisson_noise\*\*2 + background_rms\*\*2)

Emmanuel's formula is a simplification of the one I wrote, where he's using the effective gain, (effective) gain = gain * exposure time So it is in there implicitly. Does...