This was confirmed by Edwin Hubble who established the Hubble redshift of receding galaxies. MACS0647-JD is the farthest known galaxy from the Earth based on the photometric redshift. It tested the gravitational redshift to 0.007%. The Hubble constant, "H"("z"), is measured as a function of cosmological redshift. It has a cosmological redshift of 3.911. This is known as the gravitational redshift or "Einstein Shift". By then he knew of the gravitational redshift and the deflection of light. This redshift and blueshift happens on a very small scale. However, photometry does at least allow a qualitative characterization of a redshift. The relation of redshift to recessional velocity is another matter. Next, the connection between redshift or redshift velocity and recessional velocity is discussed. Hubble found that the amount of redshift is directly proportional to relative distance. He discovered a relationship between the redshift of a galaxy and its distance. Only later was Doppler vindicated by verified redshift observations.