Redshift/Distance relationship for a Non expanding model
In cosmology redshift is given by the letter z. The z to wavelength relationship in an expanding model works as follows:
A restframe source emits a wavelength range of 500-1000 nm. At z= 1 it doubles to an observed range of 1000-2000. At z=2 the range is 1500 to 3000. At z=3 the range is redshifted to 2000 to 4000 etc. The distance to the source in an expanding model is explained and given as velocity in km/s. The higher the redshift the faster it is moving away from us and the farther away it is.
In other words the distance to a source at z=2 in an expanding model is much farther than predicted for a non expanding model because in a non expanding universe the source is not moving away from the observer on earth. So that for instance in a non expanding model a star at z=2 is twice as far away from earth as a star at z=1 is from earth.
Unfortunately to date the best confirmed real actual distance of any star from earth is much less than z=1. Which is z=0.1 to the Virgo cluster. The table below assumes distance X at z=1 is a known actual real distance and not an assumed distance related to velocity, as is the case in a Big Bang universe.
z=0 (500nm to 1000nm ) = restframe
z= 1 (1000 to 2000)=distance A
z=3 (2000 to 4000)=distance 2xA
z=7 (4000 to 8000)=distance 3xA
z=15 (8000 to 16000)
z=31 (16000 to 32000)
z=63 (32000 to 64000)
z=127
z=255
z=511
z=1023(ie Microwave)=distance 10xA
Therefore in a non expanding universe z=1023 is only twice as far away as z=31. Or 10 times as far away as an object at z=1
So far the current available limits of detection in optical are via the JWST mid infrared camera. ( JWST MIR camera range is 5-28 microns. Equivelent to a redshift range of z=9 to z=49)
The big question is...how far away is z=1 in a non expanding model?
That will be hard to quantify as so far only the Virgo cluster at approx z=0.001 has a known real distance. Using various methods like parralax.
Thus in a non expanding universe the CMBR is explained as redshifted light from galaxies at and around z=1023. That is galaxies at around 10 times the distance from earth as any source observed at a distance where the light is redshifted to z=1.
The average black body spectrum of all the billions of stars in that distance parameter around z=1023 combine to give the observed CMBR. And because at that distance there is still a small variation in distribution of galaxies this also accounts for the slight graininess observed in the COBE CMBR images.