In article ,
"Stupendous_Man" writes:

Bob Day wrote:
Is modern distance modulus vs redshift data from type Ia supernovae
based on photon flux, so that the expansion of space would cause a
1/(z+1) decrease in the flux, or is it based on energy flux, in which case
the expansion of space would cause a 1/((z+1)^2) diminution?

Most measurements these days in the optical
and near-IR are made with detectors which count
photons, not energy.

Yes. But the raw measurements are converted.

What people do with the measurements afterwards
is very hard to follow properly.

You need K-corrections etc. Standard stuff. The 1/((z+1)^2) factor is
for a K-correction of 0.