What is the brightest light?

Question

I have been to wikipedia about intensity of light, and there are at least 20 different ways to classify it. So I guess it boils down to the formula E = hf, which is the energy of a single photon. Now past gamma rays, is there a maximum frequency, hence energy of a photon? How does what we can create in labs compare to what exists in outer space?

Answer 1

I'll suggest GRB 110918A, which had a peak luminosity of $L_{iso} = 4.7 × 10^{47}$ Watts. That a ten to the forty-seven - it isn't a typo.